I'm running a Raybrig NSX at the moment (I though it was the ARTA, haha...).
Anyway, on RS tyres I can pull out over 30s per stint over the AI who seem to be using RHs. I'm running six lap stints on RSs. I tried the RHs and I could just about stay ahead of the other Raybrig (I didn't bother setting the car up), but it was taking too long and too much effort (I need moneys in the fewest in-game days; UCD caught me napping.) The AI Raybrig in second place was pitting every 12 laps, and I could do the same on RHs, although the last couple of laps were a nightmare, especially when it started raining, which accelerated the wear as I was sliding around more (I love the way the grip level changes; once the sun went in, I couldn't get close to the fastest lap I set in the sunshine, and I was running less fuel!). I should add that I'm using no aids, including ABS; tyre longevity and average laptimes are no doubt much better with aids, but I'm oddly stubborn.
So it should be fun with any GT500 car on RHs, assuming you're consistent. You could drop the PP down by 50 points or so from the highest on the list (the 350Z, which isn't that competitive in my race) and have a good race; they're not especially fast around many of the corners, so try dropping the aero a bit, too, although it might accelerate wear. The Raybrig NSX seems to be one of the better cars in the pack, out of the cars I drew, so something other than that might give a better challenge. For example, I'll probably try the Standard Castrol Supra next time.