help i need a pipe!!!

help! my dad is ordering my pipe for my 250ex next week but he can cancel it if i find out it is bad one problem i dont know which one to tell him to order which pipe for the 250ex do u think will work the best i was thinking big gun and pro-circuit:huh what should i get if not those what do u think i should get instead?:confused:

I a test that ATV sport did the pro-curcit had more power, but that was on the 400EX the 250 might have different results.