Snow ball effect!!

I just got finished swapping a electric fan into my dart. My question is how can I get my rpm's up when I shift from park to drive?(904 with a stock converter I believe) I have my rpm set at 850 in park but it drops to 550-600 when in drive. My problem is with the charging system. It seems that if I'm sitting in traffic in gear idling at 550-600 for extended times my alternator doesn't charge enough to power my stereo, amp, electric fan and whatever else is I forgot. I also notice that my headlights dim quite a bit when idling at 550-600 and that's without the electric fan.

I know a simple solution is to turn off the stereo and amp and put it in park when I'm stuck in traffic. But, that's when I like it most:)

I already have a newer alternator that is supposed to be rated at 60amps. I think it's just a cheap autozone remanufactured item.

will increasing the field wire size from the alternator to the regulator help? They seem undersized for the larger alternator. what about the larger main power line , does it need to be larger also? What about a altarnator upgrade? I've already by-passed my amp gauge to get that out of the picture. Would a different stall converter put less drag on the engine?

I know I asked alot of questions.......I just want to know if I can make the fix with more than one option.