Hey Graeme,
Both Schumacher and Associated well supported at Mendip and the SW in general for 2wd. Smattering of other stuff if you fancy something different.
With 4wd, again Schumacher and Associated both popular, but then throw in the Xray XB4 as well. Numbers have been low recently, but there may be a resurgence now with Regionals running both classes on the same day.
Worth noting our main trackside support still comes via RC Octane, so worth checking with John what he best supports
Might be worth asking the same question in the Mendip Offroad FB Group (if you have FB of course) -
https://www.facebook.com/groups/285941652544337/