Looking for a better bimmer alternator

[kco325]

I'm starting to think about a new alternator... with 2 amps, 3 extra gauges, upgraded headlights & foglights, an ignition box, a few extra interior lights and my alarm all drawing extra power, I think the stock eta alt. isn't going to cut it for long.
With immediate plans to install a 2nd battery with an RV-like setup (battery isolator monitering&charging 2 batteries, 1 for engine, 1 for lights, stereo, accessories, as well as a 110v landline), I would still figure the first step is a new alternator. My lights already dim when I turn up my stereo beyond 1/8 volume.

Anyway, the eta amp is... 90 amps I believe? I'm looking for something between 120-150 I think, anyone know if I can get an OEM alternator off something else?
I'd rather keep it all Bosch, but I'll resort to some aftermarket if neccessary.
Thanks

[Furious]

there should be two different size alternators for you car, i believe a 90 and a 140 (im not too sure about that) but look into it.