I've been vaping since Nov '12, and I went through the exact same process you did. Started with eGo stuff and Vision tanks, but couldn't get enough throat hit. Upped my juice to 24MG, still failed the throat hit. Put in lower resistance wicks, boom - throat hit. I'm golden, right? No. The wick/coil assembly wore out on those after only a few days to where I was constantly fighting dry hits and burned vapor. I was replacing wicks about every 4 days and the last 2 days I was just ....... Then came the BCC tanks. Greatest idea to hit the vaping world since, well, ever. Problem was I started with a VapeOnly BCC and had unbelievable problems with leakage and gurgling, but I was bound and determined to chase the 'always-wet-wick' theory until I found something that worked. I bought a 'TABAC BCC', which is really just a T3 knockoff and uses the same wick/coil assembly. That was and still is my go-to vape. I would highly encourage you to give your T3 another shot, except take that little silicone cup in the top of the coil and turn it upside-down. It'll allow more juice to the wicks, but still won't leak or gurgle. Also, you mentioned getting a hot vape when you changed to a 1.8 ohm coil. The 1.8 ohm coil is made specifically for batteries that are fixed at 3.7V. Anything more than that and your risk of popping them goes through the roof. If you're using an adjustable voltage battery, set it at or near 3.7 and adjust on .1v increments to suit your taste. The trick, really is not in voltage or ohms, but wattage, which is volts x volts / ohms. (3.7vx3.7v/1.8ohms=7.6W) A battery mod like a VAMO or a SVD or EVic or something similar will allow you to set the wattage you want to vape at and make all the adjustments for voltage and ohms for you. No thinking required, just the same vape from the first draw until your battery runs out. I bought my VAMO V2 about 2-3 months ago, and it's the best thing I could have done. The good news is that they're getting really cheap on FastTech.com now. The bare V3 is going for about $40 right now, and the complete kit including the batteries, charger, and a Vivi clearo is right around $60 if I'm not mistaken. The bare V2 is around $30, and the bare SVD is about $40. I set my VAMO at 7.5 watts and don't even bother checking the ohms on my coils anymore. Now, for the ProTank. That's been a source of a lot of frustration for me too. It seems like they hit really well for about a day or two, then the flavor and vapor density just goes in the tank. I've tried cleaning the coils, and adding or removing wick material, but nothing seems to bring them back to the first hits. When it hits right, though, I LOVE the flavor, because the glass tank just gets out of the way and lets you taste nothing but your juice. I hit one of those exclusively for about 2 months, but just last week went back to an MT3, and I'm back to getting WAY more vapor again, and coils that last upwards of 2 weeks. Unfortunately, I think those coils are not long for this world, because the smaller EVOD/Protank/T4 styles are going to be taking over. I was on a site yesterday (can't remember which one) that had a bunch of T3 style tanks on clearance because they said that the coils are not going to be made any more. Other sites still stocked them, but I can't help but think they're on the way out.
You mentioned having spent upwards of $200 on gear since you started. How much would you have spent on smokes in that time? WAY more than $200. That's how I justify my eternal quest for the perfect vape... I'd have to spend a whole lot more than I am to even come close to what I would have spent on smokes. My wife even smokes in the house and the car, and I haven't had one since December. I've taken hits off hers every few weeks, but I give it right back because it just tastes like ..., and I remember again why I quit to begin with.
I'm definitely going to reseach some more about how dudes are making the ProTank work for them, but for now, I'm rockin my MT3 and lovin' it! Good Luck, dude!!