hey
ther is one relatively cheap diy way...
buy second hand rear axle from a e36 318ti or 323ti compact --> bolt on
and for the front brakes you have to buy the parts on the picture, and also front suspension of a e36

the brake discs you can buy then:
286x22mm: E36 325i-328i, good start
300x22mm: E46 328i, better
325x25mm: E46330d (only with 17" wheels and they brake very well, i have those on my e36)