Any TB larger than the factory size will give you a notable better handling car... but its all a "package". In brief, from what you're suggesting, and having a BB, I'd suggest about a 1.10-1.12. And, get some better shocks... double adjustables are the way today... you can fine tune the ride. Also, work with your tire pressures to further fine tune the ride. Try to level-balance the four-corners (front sides, rear sides) and eliminate any large body rake.

I love my 1.24 TBS and 225/inch mono-fiberglass leafs, 1.25 front sway bar, 1.00 rear sway bar, Red Koni adjustable shocks (being replaced by double-adjust QA1).

Mopar Mitch "Road racers and autocrossers go in deeper and come out harder!"... and rain never stops us from having fun with our cars... in fact, it makes us better drivers! Check out MOPAR ACTION MAGAZINE, August 2006 issue for feature article and specs on my autocross T/A!