Just poking around in here...

[Bean]

what they said
to get it drifting you don't need alot as long as most parts on the car are still healty. Aftermarket bushings are easy to get and not very expensive and firm up the car quite well considering your bushes are quite worn after 25 years... some lowering springs won't do any harm either and regarding LSD in my humble opinion a good rebuild of the stock one if it's not lockig properly anymore is all that's needed (there are some aftermarket rebuild kits as well to have a little higher lock rating)...if you don't do a lot of highway driving or don't care about high rpm you could also invest in a shorter CWP to help torque at the wheels abit

for interior stuff your best bet are probably people build there AE86 into racecars as they usualy rip it out...