Your battery doesn't really have much to do with the new accessories, more of an alternator that will handle the load, which it sounds like V/A has done. The electric fan will add a load as well, make sure to relay it to get the amps manageable.
Get a Deka/East Penn, one of the very few American-made batteries still out there. If you want a decent cranker, a group 78 (BCI number), like a 678mf, which has 690cca, 850ca, and a 110 reserve.