retuned???

[jd8181]

i was looking at getting a new set of pipes for my bike. i was thinking either
#1  http://www.hookerpipes.com/product_p/27401-3hkr.htm  or
#2 http://www.hookerpipes.com/product_p/27401-4hkr.htm

i have had my bike sert and i was wondering if i will have to get it retuned?? or if it will be ok if i put a different set of pipes on?? also which set of pipes would look better on my night train??