Second the bottomline with a nice on/off.
Then after that, the barrel:
Option One: a Tightstick (http://pumppb.com/index.php/topic,2188.0.html
Option Two: Lurker Eigenbarrel (http://www.lurkerpb.com/barrels/the-eigenbarrel/
Option Three: pick up a cheap freak kit, or if you're lucky, a cheap Deadlywind, which requires Freak Inserts.
I personally don't like the TechT, mostly for the fact I don't think it's a long enough control bore.
Lastly, the tank. I recommend a 13/3000 if you want fast and light.
I had a Trracer with a bottomline on/off, Lapco .682, Ninja 13/3000 and a Dye Locklid APP hopper. That thing shot darts, and was super light. That's my personally recommended setup, doesn't mean it's the best though.