I know a great mechanic in town that I've used for a while, should I take it to him or opt for an Acura dealer instead?
The NSX alignment is neither simple nor straightforward. I would take it ONLY to someone who does a lot of work on NSX's (which means not just ANY Acura dealer, either). Greenwich Acura is one such dealer in Connecticut.
can anyone suggest any optimal alignment settings for the street?
Even on the street, it depends on your driving style. For most folks, the 1993+ factory alignment settings (see the Alignment section of the FAQ, under the Tires and Wheels heading) should be fine. If you drive VERY aggressively on the street and don't mind rapid tire wear, you might consider the '91-92 settings. If your miles are mostly highway miles, you might consider the "alternative" setting shown in the FAQ.