at sherwin williams, I was able to find a 'precatalyzed epoxy paint'. they recommended an oil based primer. I've used it and it seems to cure nice and hard, and its supposed to be pretty water and mold resistant. Also only 1 can of paint instead of 2 like most epoxy paint.
Something to point out (as I was reminded by others), is that you do not want exposed untreated lumber resting on a concrete, or wood ground. I notice from your initial rendering that you do not plan to have any ends resting on the ground, which is great. The dry wood can soak up moisture and warp just as badly as the treated lumber if not fully protected.
I would make sure to paint any wood surface that is resting on the ground (aka, the bottom of the stand, and probably surfaces adjacent even interior ones).