Long post, but I've answered some questions about usage (esp. leakage) in here for which I've never found another answer on ECF (leakage has been the bane of my 2yr vaping existence). Hopefully it'll be a good reference.
Cartos/Clearos:
+1 for the MT3S -- I love these, probably my favorite.
Huge caveat: they can (will) leak. You can't let the part where the wick is get exposed to the air in the tank, it will break the vacuum and juice flows out. This'll happen whenever you lay them on their side or run them below ~1/3 full. Also terrible on an airplane (pressure changes make juice flow out the end).
Fix: when it starts to gurgle or hits seem vaporless, pull it off and see if there is juice on the battery connector. If so, stick in a paper towel or kleenex or whatever to absorb the fluid. Wiping up the bottom of the atty isn't much good, it'll just get messy again (ref: blowing it out below); at this point you're going to need to restore the vacuum. Unscrew the atty from the bottom and refill it. In a pinch you can just unscrew the atty, blow it out, and wipe up the juice that runs out the tip with a kleenex, but it'll probably keep leaking until you refill it.
Tip: I generally keep a syringe handy -- when you flip it upside-down and pull the atty from the bottom, juice will flow out the mouthpiece (viz., drip tip). If you watch carefully and have the syringe ready you can suck the <0.2mL into it and reclaim it. Else you'll have a bit of waste and a hell of a mess. You'll also want to blow through the bottom end of the atty (lips around the textured grip, chimney pointing away) into a paper towel or what-have-you to clear out what's in the "vapor column" (that tube which carries the vapor from the coil to your mouth); optional but it'll save leakage or juice in your mouth while the vapor column empties itself of the previous mess.
Additional potential issue: if you screw it on and it won't fire, you may have screwed it on too tight. Hand tighten, don't overdo it! It's a simple fix: grab an eyeglasses screwdriver, syringe tip, paperclip... something long and thin and metal, stick it in gently between the "button" and threads on the battery, and lift the button a bit. Do this a few places around the outside, put the MT3S back on and it'll fire. Only happened a couple of times for me, but if I hadn't known this I would've thrown perfectly good attys away.
Another option: I've added a
Smok DCTank to my rotation. Any tank with a baffled cartomizer will be about the same, but I like the Pyrex tube and it's more robust than the EVOD (which needed some superglue on the window to keep it from leaking).
Boge F16s run like a dream, and they don't leak -- even on an airplane. I like SR, LRs seem to burn 50/50 or 60/40 if I'm on the fixed voltage eGo. Though most of the world seems to love 1.5ohm, they'll spend your battery faster even if you do figure out how to make it tasty; I have absolutely no complaints w 2.5-2.8ohm. Haven't tried non-Boges yet. MAKE SURE that you follow the videos for priming the baffles, or you'll torch it!
The problem with these is that they are loud; a coworker walked by and asked me to fry him some bacon too, it's exactly what it sounds like.

MT3S is much quieter, much friendlier sounding. Both taste almost the same to me, same throat hit, same vapor production, about the same capacity -- just depends on your tolerance for leakage. Grab a eGo thread cover adapter thingie for $2.50 or these look weird; they also let you play with airflow.
I also enjoyed
CE3s. A little more awkward, less sexy looking (someone asked if the drugs I was smoking in it were legal), have to refill with a syringe, and will also leak if you break the vacuum at the bottom... but I used these things for about 1.5yrs of the 2yrs that I've been vaping and loved them. When you're filling, invert it so that the mouthpiece is down, stick in the syringe full of juice (~0.8mL), pull the plunger back about 1 - 1.5mL to clear the atty, then just push the plunger right back in. That will prevent you from forcing old fluid in when you're refilling it, which will leak out during your first few hits.
I walked away from these because of recent bad batches which just poured juice out the end; no amount of fiddling (including full disassembly) could get them to stop. They also leak like hell on an airplane; anything without baffles (viz., stuffing as in the tank cartomizers) will.
Batteries:
+1 for eGo 1000mAh batteries, esp USB-passthrough eGo-C and eGo-C Twist. I like the latter better because of the voltage control, but the fixed voltage eGo-C will change the color of the button to tell you when you're <50% and <10% charge so you're not surprised when it dies. USB-passthrough is essential -- you can always find a USB charging cable and a laptop or car charger, so when you're 2.5h from home and it dies you aren't stuck craving and cursing your lack of forethought. The eGos have lasted 6mo on average before the button starts acting up or they suddenly need recharging more often -- that said, I still have and can use my first one. Only issue: I dropped a couple (on carpet no less, but from waist height) and the button broke. <shrug> Don't drop things.
Juice:
Vermillion River's Kentucky Applewood will never steer you wrong. I can't find anything else that I enjoy for more than a couple of weeks. When friends/family even smell anything they say it reminds them of carmel apples or pancakes. It doesn't
just taste like either of those, it's far richer... tobacco also mixed in? Nutty something? I can't figure out what's in it, try it yourself rather than take my word for it. It just rocks. If the guys at VR want to share the recipe to compensate this little plug, you have my number.
[NO, none of the above is sponsored. I'm just a (little-bit OCD) guy who is loving the clean smelling clothes and 10 extra years of life, trying to share what he's learned.]
Enjoy being cigarette free!!! Just be careful, PVs are hard to put down... my daughter used her pacifier less than I vape.

I cannot, absolutely cannot, imagine ever smoking a cigarette again. The thought disgusts me, and I was a 1pk/day Marlboro Medium fan.
Enjoy!
I wouldn't start with a vivi nova, they hit really light. One of the major factors to quitting smoking, whether or not you'll be successful, is the drag or hit factor. Does it hit like a cig? That's probably what drew me to PV devices. You can get say a Kanger M3TS with a couple small batteries and you'll be set. Yes, it is larger than a cig, but if your doing this to quit, it's a sacrifice you may need to make....priorities.