Honestly I'd do 3 things if I was in the OP's shoes before getting crazy with fixes or buying a ho alternator...find out what the standard voltage range my vehicle charges at, then have the battery and the alternator tested to see if they're the problem, and do the big 3 (it's fairly cheap to do and might be all that's needed on a 1k system)
I ran 2 ab 15's off 800w on stock electronical with 4g cca power and ground in my saturn vue (90a alternator and plain old lead acid battery) for a couple months without any real voltage issues...I knew I was gonna go a fair bit bigger power wise and started doing electronically upgrades to support that...only changes I would've made if I was staying at the 80p-1k range is an agm under the hood, big 3, and swapping power and grounds out with copper...
I ran 2 ab 15's off 800w on stock electronical with 4g cca power and ground in my saturn vue (90a alternator and plain old lead acid battery) for a couple months without any real voltage issues...I knew I was gonna go a fair bit bigger power wise and started doing electronically upgrades to support that...only changes I would've made if I was staying at the 80p-1k range is an agm under the hood, big 3, and swapping power and grounds out with copper...