Curvy is good, front end swap for K-Tech progressive springs or something similar, gives a much better ride for next to nothing (except time spent fiddling).
As for the back end, I never did find the need for anything else, although if I had my time again maybe sort a way to fix a cushion to the seat which is not too comfortable on long rides.
Curvy is best, leave the bodywork well alone. Sort the forks, ride it like you stole it.
