Well, if your talking about going to comps, then your going to need a lot of power, and money. If money isn't an issue, then try this set-up:
15" RE Audio XXX: http://reaudio.com/specs.html#sp_xxx
AudioQue 2200D: http://www.audioque.com/aq/AQamps2200D.htm
0 Gauge Wiring Kit off Ebay
Remember that with this much power, you are most likely going to have to upgrade your electrical system in your vehicle. This means buying an HO alt. and doing the Big 3 Upgrade to your vehicle.