Hi im putting together a system before i buy it and i want 2 Sundown SA-15 D4 V3 subs, Orion xtr1500d.1 amp, and i was wondering how many amps i need my alternator to be. I have a 2004 mercury mountaineer 4.6 v8, and i think it has a 130 amp alternator. Im going to do a big 3 upgrade, and put in...