alternator performance

I have an 88 Oldsmobile Delta 98. It has a 105 amp factory alternator, and charges at about 13.4 volts. It's less than two years old, a refurb i bought at a local parts store. Some of the diodes are already burned out. I'm looking to find an alternator that can put out maybe 200 amps, and be able to maintain at least 14.4 volts.ive had my subs unhooked for the last few months to get by until the weather warms up.im running two rockford bd 1000s, a rockford bd500, and a jensen 400 to push my full ranges. i have 4 guage all around, a one farad strike cap in the trunk that i got for cheap, and im cheating all of the rockfords fown to one ohm. i need to come up with a somewhat cheap way to provide enough juice for all my power-hungry devices. Any advice would be greatly appreciated.

Thanks,

Aaron