If you go with Mr. Alternator, get the casing powdercoated. This will help it's efficiency by dissipating more heat. The hotter the alt gets, the less efficient it is. And with that small casing, it gets hot pretty quickly.
Another thing to consider is swapping it in. NWOR will require some fabrication/trimming. I'm pretty sure that excessiveamperage is a direct bolt on. I know for a fact that Mr. Alternator's is a direct bolt on.
You might want to consider swapping in GM unit. They have much bigger housings that can allow for more upgrades without sacrificing performance. Do a search for my user name and alternator. I've been through the trials and tribulations of upgrading. For example:
http://www.yotatech.com/showthread.p...r&pagenumber=2
Hope it works out for you.