Which alt to use ?

There's lots of Post on this. h
Here's one.
EZ Wiring Alternator Wiring (Denso)

You can but Alt. with correct pully. I run a 60 amp but there are up to 150 amp ones .Here's a 100 amp.
Toyota 4Runner Pick up High Output Alternator 100 Amp 22R 85-92 | eBay