I'm about 99% sure that if you walk into Badlands and ask to be AV'd for this board, all you'll get is a blank stare in reply. Take a peek into the AV'er list and PM them instead (or conversely, as others have suggested, Army Issue should be pretty close to you and they AV).
IMO, the TAR looks kind of funny if you paint a pattern on it. But if you're set on doing it, for a pattern as intricate as Blue Tiger, you might want to look into hydrodipping.
Upgrades; the TAR runs a V2 gearbox, so most standard V2 upgrade parts will work. If you want faster trigger response, get a mosfet, 11.1v lipo battery, and maybe a better motor. If you still want better response and higher ROF, upgrade the gearbox itself with lower ratio gears and other components (you may want to get a tech to do this part). For better range and accuracy, get an r-hopped barrel.
Primary: Custom VFC M4 - KJW KC02
Secondary: Custom TM PX4 - KJW Mk1 - KJW M9
Camo: Pencott Greenzone - Pencott Badlands - MARPAT