There are lots of options, just depends on your skill level, the size of your budget and how hard you want to work at it. Baer sells brake packages that go all the way to 15 inch rotors. DoctorDiff has 13 inch kits, I build my own brake kits using Viper or Porsche parts.

Fikse will build you custom rims that are lightweight, super strong and the correct offset. Lots of performance tires are available you just need to figure out what size you are willing to put under the car. Really good shocks like Koni are available or you can step up to even higher quality stuff with a little fab work.