i would suggest at least the rear motor mount....get the cp-e one its a great quality piece and it is real BEEFY...
as far as stepping up to all 3 motor mounts...if you have the cash to spend, go for it...it will def make the speed 3 feel different from stock...especially when you go WOT exiting out of the corner....the stock mounts have so much slack in them its ridiculous...i would suggest the medieval trans mount at the very least...I have that and the stock pass mount, it works great!