You have to decide how much money you have to spend on a car before you figure out the rest. Clearly 5th gens are newer, though there are nice 4th gens available.

The 5th gen was the 'return' to the original notchback styling, and according to some still looks current with modern car styling. All cars were only available with VTEC, though the models differentiated in features. The type SH has ATTS, which makes the car corner faster/differently than other FWD cars. There is a sportshift/automatic version that will be cheaper than a base 5sp due to the fact it isn't as desirable, and the SS feature has an extensive history of problems. The "Base" model has the 5sp manual tranny.

With regards to 4th gen models, '92 was the first year of the model, and it didn't come with VTEC. There was the S, with the F22 engine, or the Si w/ a 2.3L. Some Si cars with that engine had 4 wheel steering, they are rarer, more expensive and more expensive to maintain (I have one). 93 to 96 saw the SiVTEC model brought into the line-up, for reasons of anomalies or weight, the 93 VTEC was the fastest Prelude in stock form, making it highly desirable among Prelude enthusiasts.

I'd recommend looking around at a variety of Prelude Specific forums to collect as much information as possible in this case: Try hpoa.org, preludeonline.com, absoluteprelude.com and so on....