Hey there headcheese (great name btw).
So you're ready to make the step up to mechs and RDA's, huh? Nice. Before you begin, it's worth it to start researching battery safety, ohm's law, and all that good stuff which so many other newbies seem to ignore. Understand the limitations of batteries, and prepare yourself from experimentation. It took me a good amount of time before I started building coils that really fit my vaping style.
For places to shop,
KidneyPuncher always gets a vote from me. They have fairly priced stuff, and it's all QC'd (quality control'd) meaning you're FAR less likely to get a crap device from them than from, say.. FT. Also they offer returns on most purchases, which is fair.
Not sure what your budget is like, but if you want an all-in-one type deal, the
Valkyrie Hybrid is a pretty good choice (and it's on a crazy sale right now, $140). As a hybrid, it comes with an RDA designed specifically for this mod. The downside to this is that you can't use an RDA of your choice (if that's what you want to do). On the positive side though, it looks really nice straight out of the box (no need to mix and match), and from what I've heard it really performs well. It runs on an 18650 battery which, depending on your build, should last you a decent bit of vaping. For me, at a .3 ohm coil, 2x 18650's (1 primary, and 1 backup) can last me an 8 hour workday.
Another good option would be the
Magneto II (there is also a brass option). I can't speak for the second version, but I have the first version, and it remains my go-to "beater" mod. If I'm going somewhere that I might get too sloppy/lose my mod, I bring the Magneto. It's cheap, it's SUPER reliable (not a lot of moving parts means not a lot to go wrong), and it doesn't look half bad. Since it's not a hybrid, like the Valkyrie, you're able to put any RDA or tank on top of it. Additionally, it's a telescoping mod, so you can fit any style battery in there (18350, 18490, 18650..) which makes switching from a RTA to an RDA very possible, and quite easy.
In terms of RDA choice, I highly recommend the
Doge RDA. They just recently came out with the
"Doge X", which is a variation on the original Doge. The only issue with ordering from Congrevape is that it's a kickstarter-style site. You need to wait till the end of the month before they start shipping. I have a written review for the Doge RDA in my Blog Posts.
So if you're not looking for that, my next best recommendation would be the
Infinite Tobh Clone. I own 2 of these, and both of them get a fair bit of use. Very spacious deck makes building easy, airflow is pretty great, but my favorite part is the fact that it has a driptip-topcap. So when you go to drip, rather than pulling off the entire topcap, you can just pull the driptip-topcap part. If you started off on a Tobh-style atomizer, you won't realize it, but it makes dripping SOOO much easier compared to a Nimbus or Igo-style topcap situation.
Anyway, I think I've given you a couple things to think about. Let me know if you need any help with purchasing decisions!
Any advice? I've already tried tons of juices, and have spent a lot in my short vaping career, so I'd like to keep it simple and cheap for now (clones?). I figure I can splurge in a month or 2 on some authentic gear, if I like dripping (once my vapemate tells me so!) 
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