any advice?? need good setup

i think i'm gonna take out the rears for show. if i do compete, it'll be on a local level, nothing professional. I mainly want it for show, but i don't wanna be a low finishin' guy in comps. ok (writes down 4 subs), so a 4 sub setup should get me bumpin'. any advice on how to power them and on other speakers/tweeters? Also, does it matter where i mount the subs? Will the sound quality differ depending on where i mount them? thanks. u can email me at evobikes@hotmail.com