What other parts can i use on my 1990 audi 90 quattro?

i have a 1990 audi 90 quattro 5 cyl 5 speed AWD and it needs a new coil spring, what other cars can i use for parts for my audi? and how much will it be to get some one to put the coil spring in?What other parts can i use on my 1990 audi 90 quattro?audi willbe the best and you realy want a pair !