Ok, 99% of these suggestions aren't terrible, but they aren't great either. One guy got it right-ish (iamme123). The answer is the eGo C Twist. You can buy "replacement batteries" from altsmoke.com. They are genuine JoyEtech eGos. Fake Twists come cheaper but you pay in pain and suffering in the long run. Get an authentic JoyEtech eGo. They go for about $26 a piece. Don't forget an eGo USB Charger, you'll need that.
I bought a knockoff a little over a week ago to save some money and the thing doesn't twist like it's supposed to. I have since loosened it up by breaking it in, turning and turning it with a rubber jar opener gripper thingy and now I can just BARELY (if I focus my chi) turn it by hand without the gripper.
A real eGo Twist has white letters on the side of the battery "eGo C Twist", a logo on the bottom of the battery cap, and logos on the part where you screw in the atomizer. Altsmoke and Sweet-Vapes.com have these. They only come in two sizes, 650 and 1000mah. Any other number (such as 900mah) is a fake.
The best mini tank clearomizer is the E1-V which you can find at discountvapers.com .
That aside, if you can't get your hands on one of them the Vivi Nova Mini pulls a distant second.
If you would like to learn everything you need to know about ecigs with a quickness just click the link in my signature to The Vapor's Handbook and all will soon be revealed to you.
P.S. Blu is owned by Lorrilard, the company who sells Newport and Kent cigarettes. Please don't support them any more than you already have. The last thing vapers want is big tobacco to make more money off of them any more, or try to change the game on us. It's ok, we know you didn't know, but now you do. Use this knowledge wisely.
The provari is a good tube mod APV but it will also run you well over $250 for a top-of-the-line model.