Yeah, I'd also say neoprene is probably the best thing to go with.
Barbari has a good website that you can use to go through and select everything to customize a fit to your specific car. It's probably a little more costly, but to ensure a tight fit and no sagging, it's one of those "you get what you pay for situations."
The lack of proper fitting of my seat covers in the past made me rip them out! So annoying and frustrating! Plus, have you ever seen how pitiful some of them can look if you happen to get the kinds that fade? Ugh...
Here's their website! --> Neoprene Seat Covers - Neoprene Truck Seat Covers | Barbari Seat Covers