Are you in Stockton CA? I used to live in Modesto CA during 91~96, from 91 to 96, I think I saw a grand total of 1 NSX in Modesto, and it was at Modesto Acura dealer lot.
you are in a win win situation regardless of your choice.
If you want a better looking car, go with NSX no regrets.
If you want performance, go with M3, or 97~03 NSX.
If you want to save yourself 15K to 20k in hard earned cash, go with 91~93 NSX, you can always use the money you saved towards next toy.
you should see NSX park next to M3, you will notice the difference, one of the thing I like best about NSX is that the sitting position is so low yet so comfortable, my NSX is stock ride height, it almost make all other cars seems like SUVs in comparison.
You can park NSX next to almost any exotic cars (including HSC, if it ever come out), and it will hold its own in look department.
Next M3 should not be too far away either.