i have 8 gauge wire running to my 760 watt amp and it is fine. i would get the lowest gauge you can find. it would be much better.also don't buy wires from walmart they are cheap as hell. go to circuit city or best buy or your local car audio shop
i installed my system my self but if you don't feel comfortable doing it i would go to your local car audio shop and have them do it not circuit city or best buy