It may be a case of what is available and the 'other' things that you want. If you want the larger 3.2 l engine, the 2000 and later ABS system, power steering ... then you are into a later car and the majority of later cars are targa. Coupes are available in the later production years ; but, they are rare and you are probably going to pay a price premium.
NSX Prime used to have a wiki with the changes by production year. That is no longer available; but, it is archived on the wayback machine internet archive.
web.archive.org
Go through the changes by year and it can help you decide whether there are important features you want that may predetermine your coupe versus T roof decision.
If it comes down to just a targa versus coupe decision, I have a 2000 targa. I purchased largely on the basis of what was available at the time (2011) and what was in good condition with a good maintenance record. The targa was a novelty and I used it on nice days at the start; but, the novelty has worn off and in the last 8 years, the only time it has been off is to clean and lubricate the gaskets. If I could find exactly the same car in a coupe I would take it over the targa.
The targa versus coupe will be a subjective assessment. If you decide you like the idea of the targa, take into consideration the following:
- the front (A pillar) and rear (B pillar) weather stripping is mind buggeringly expensive to purchase ( around $1500 list each) and very difficult (expensive) to replace. You need to be careful with the gaskets and do regular maintenance on them to preserve them.
- the roof panel is moderately heavy and awkward to remove / install
- store the roof panel in the clamshell over the engine and it will get really hot. In order to re install the roof panel if it starts to rain while using the car I have some insulated gloves in the trunk so that I can handle a hot roof panel after using the car
- I have a black interior. Park the car for 15 minutes in sunshine and you will burn your cheeks on the leather when you get in.