I think you could probably just leave the wood. maybe throw some snow on it. I mean thats what the pros do and it works for them ha.
if you have the extra money you might want to get plexi or something like that.
I would say when winter rolls around try it out with only wood. If you're sticking you can put something on it.
For supporting it the best would be to lean it against a solid tree or something. If you have to make a stand for it out of 2X4s make it strong. when people start jumping on it, thats a lot of stress. there really isnt a light weight way to do this.
I have a small wallride in my park and its just wood. Its the heaviest feature i have and the wood slides just fine