I wouldnt get too hung up on using discs at the rear
My own car is drum braked with standard 2wd fronts and can stop as well if not better than some of the fast cars i have owned
I have had a few nice cars too, integra type R (very good at braking), m3 evo, impreza, 300zx TT etc etc
Alot of people fit discs but then have to fit a valve to reduce brake effort at the rear so that they dont lock before the fronts for IVA, and your own safety for that matter!
Drums do look pants though
Lsd is always worth having although ive never had a moment where i thought mine needs one apart from one particular corner at a track day when it was damp and the inside wheel kept spinning up, but apart from that the other 4000 miles went swimmingly
............... and quickly
