a D snaffle is pretty good
Snaffles are always my go to so I would say a slow twist d ring which is a little more than just a traditional snaffle and isn't as harsh as some bits but is still effective
You don't need anything excessive please understand that just having a hot horse doesn't mean you need a five inch shank. Snaffles and 1-2 inch Pelhams with low or no ports are just fine
I ride an older hot horse and i use a D ring corkscrew and it works great!