stock parts/used are fine for repairing the damage.
i personally love ulmer racings clutching on my sled. allen customizes it for you and your style of riding. in my case, i took it out of the box and put it on the sled. did not have to do a single adjustment as it was bang on for my type of riding.
track, that is all about what you want to do with the sled. if you want to be fast on the lake and straights, you have to put a shorter lug track on. if you want better off trail, you have to put a larger lug.
i personally love my ripsaw as it does everything i want it to pretty good. my only change would be to go to a fully clipped track for the next one. just one thing to consider, some guys like different tracks because it suits their riding style better. still love my ripsaw though.