If you are Cutlass Supreme shopping, I'm the guy you wanna talk to. I had one for 2.5 year and I know a lot about these cars.
Stick with the 1995, the upgraded interior is worth it. If you can find one with rear buckets intead of rear bench, grab it. The rear buckets are supremely comfortable, the rear bench is a park bench.
Go for the 3.4 DOHC. In the coupe the 3.1 was adaquate, but in the convertible the extra weight really hurts things.
The 3.4 has some issues you should know about. The alternators have trouble and they are a major bitch to change. If you have the alternator go, make sure and take it to the GM Goodwrentch dealer. Once they replace it, it's under lifetime warrenty.
Check the timing belt with every oil change once past 60,000 miles. It's only two screws to pop the timing belt cover off and look. The timing belt job is expensive and shouldn't be attempted on your own, but you only have to do it every 80,000 miles or so.
Watch your transmission fluid level. I had a few instances where I would be driving "enthusiasticly" and make a hard left turn and the tranny would slip out of gear. If your fluid level is low and you're making a hard left, all the fluid sloshes to the right and starves the tranny.
Never put the top down without closing the release handles first. You can bend some of the mechanism.
The boot is a bitch to put on.
If you have any other questions, let me know. You know where to find me.
P.S. And let me live vicariously through you, I miss my Cutlass convertible a lot.