Commodore V8s: Plenty of parts support, bulletproof in stock form, ballsy af and easy to tune if you wanna mod them
XR5T: sounds like a Mini V10, practical AF, engines have issues but if you leave them alone, you'll love them.
VWs: driven mostly by wankers who love to vape and spend more time worrying about wheel clearance than performance, but they're solid cars. Do a Golf right and they'll go like the clappers. I'd take a GTI over an R anyday, but i'd rather walk than have to deal with all the CELs.
IMHO, get a Commodore. VE SS or Calais V wagon to be exact. If you have an LS-derived engine, you automatically win. Then again what kinda JC member would I be if I didn't recommend a Commodore.