Dunno how useful this info will be, but the 3000GT alternator goes up to 110 amps for the VR4s and the loaded SL models. It doesn't look like it'd be a bolt-on swap for the 4 cylinders, but maybe it's possible to shoehorn the 3000GT guts into a 4 cylinder alternator casing.

For anyone looking to power a whole lot of stuff, the Evo X alternator is 130 amps.