The rs-4 isn't a good autox tire. It takes too much heat. I had a set for hpde and tried them at autox and they only started sticking after the 5th or 6th run on a warm day.
https://grassrootsmotorsports.com/ar...-buyers-guide/
Pay attention to the "warmup" column in the table at the bottom. The best autox tires have A warmup and A time trial pace.
RT660 are pretty popular. If you're novice and not really competing for top spot something B/B will be fine if you can find sizes that work.
These rt660 would probably work well for you.
https://www.tirerack.com/tires/tires...60XL&tab=Sizes
https://www.tirerack.com/tires/tires...60XL&tab=Sizes
The re71rs I'd go for this probalby
https://www.tirerack.com/tires/tires...RSXL&tab=Sizes
https://www.tirerack.com/tires/tires...71RS&tab=Sizes
If you're willing to run the 18" wheels tires do tend to be cheaper.
Id price out a couple brands though. There can be a considerable difference. 255-275 fronts, 275-295 rears.