Let me put things in perspective. On *ANY* other car, the 95 would cost a lot more money. The reason they are the same, is only because the NSX holds its value incredibly well. Is that really justified? I don't know. If you ask me, I would say no. I don't mean any disrespect, but I think a lot of owners on this forum do not have a clear take on what a high end car does on the market. They are somewhat spoiled by the way the NSX holds its value.
I would get the 95. I know a lot of people talk about the coupe being stiffer than the Targa, and if you think you will never use the targa, they are right. But honestly... unless you are going down a track at Mach I, the targa, certainly with the top on, has plenty of torsional rigidity. And when its nice and sunny, I for one certainly do enjoy hearing the sounds of my car with the top off. And so do my passengers.
Everytime I dig deep into my NSX, I see little things that are different from other "02+" cars. Honda, like many manufacturers, makes routine and unanounced updates. It can be a piece of foam behind a panel to keep it from rattling... but so many of these changes happen... and to the person that does not know, a 91 is the same as a 94, a 95 same as a 2001, and a 2002 same as a 2005. "Same", is a very relative term.
One car is 4 years newer than the other. Yes, a little more milage but it is a Honda. If you want to keep this thing as a garage queen and baby it all the time, then yes get the 91 and don't drive it much. If you want to actually drive the car, get the 95.