V6 front brakes are the same as the 4 cylinder fronts.
Get some *good* pads, rear V6 disks (hubs, ebrake cable, brake line, disks and calipers), and braided brake lines. That should be plenty as long as you don't have a leak somewhere in the system.
I'm running V6 brakes with stock brake lines and haven't noticed much problem with my 280+hp Camry... It'll slow me down just fine from 120mph to sane speeds just fine, and does great at the end of the drag strip.
-Charlie
Edit: Alltrac/GT4 rears don't bolt on to the FWD Camry (they bolt on to the Alltrac Camry though!). Fronts might be a minor upgrade if you can find the twin piston calipers. All you need is the caliper, caliper bracket and disk.