I'd agree that it depends completely on how you plan to use the car. My RT/10's roof has been on the car once since I bought it. The windows have never been in since it came here. "Real" windows don't show up in an RT/10 until 1997. Mine is a fair weather toy...it's not going out in the rain anyhow.
I have both a '96 RT and a '00 GTS and never noticed (perhaps because the roof is never on the RT) a head room problem or major difference. Perhaps guys taller than 5'11' can speak about that.
I had a '94 years ago and sold it. From that day on...I missed it. When I was able to get another RT, I only wanted an early car. Some folks that think a '92 is the best bet, but they're costly and don't have A/C.
(In fact, when shopping...all the really low mileage early RTs did not have A/C..and that's probably why they're low mileage.) Unless having the first year is important to you...it's more affordable to get a '94, '95 that looks almost the same.
When I was looking, lots of folks tried to talk me out of a Gen 1 and into a Gen 2 RT. While I appreciate the differences, like roll up windows, the later Gen engine's higher HP, etc..I really wanted the earlier car interior with no air-bags, no windows, etc. The '96 has the earlier interior, no windows, smooth hood, engine of the early car...but the GTS suspension.
Price of the car you missed? Probably a little high, but there's a premium for the mileage. The fact that it was all stock is important in my opinion too as Viper parts are expensive.
Good luck in your search...there's one out there for ya.