2001 mustang stereo/battery/alternator

ok i have a 2001 mustang. im running 1 audiobahn 10 inch 1000x in a sealed encloser and 1 el1500 bazooka amp. this is all connected to my mach 460 system via a navone hi low convertor 4 ga power ground and it really sounds great. now to lead up to what happened---- i tryed to jumpstart the car (winter time) with another battery (dumb azz) causing a good sized spark. after that the problems started. headlight/interior/radio light dims (bass) battery discharges when left for a coupla days etc. the headlights would dim when bass hit PRETTY GOOD TOO enuff to notice it . the battery will not hold a charge for more then 4 or 5 days WITHOUT A SYSTEM INSTALLED and without being driven . im thinking a diode (so i have been reading) in the alternator (130 amp) has gone bad from a short causing the parasitic drain as well as the under current. when a friend of mine and i tested the system it was only drawing 35-42 amps with high beams/fogs and system playing. didnt sound right. to me it should be drawing putting out more. so i purchased a Mean-Green 200 amp alternator which was only 45 bucks more then the stock 130 amp so might as well go large. DO YOU ALL THINK I DID RIGHT? i didnt want to get caps for they were just a band-aid for power problems.... opinions much welcomed!

i think this might help but your battery might have suffered damage from draining to nothing..check the water levels in your battey and check the current stored in your battery when the car is running and when it is off...this will tell you if your battery needs to be replaced2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR

2007 USACI World Champion

2007 World Record

2006 USACI Finals 2nd Place

battery is brand-new