Last night I ran BK Bars Rear and Holeshots Front and was hooked up.
I could be wrong as I'm fairly new to the 4wd thing, but they mostly stock Kyosho and AE parts so the ZX5s and B44s are well supported. I don't believe there are any HB parts.
You are correct, doors open at nine and racing starts at noon(ish).
The track is more technical then fast so bring your driving skills.....not a super fast motor and battery.

The current layout is actually designed for 17.5 motors so even if you're running stock.....you could be competative.