Wood frame weight support carpentry question

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I'm building a wood stand for an RO water tank (cylindrical plastic garbage can), the weight will be about 350 lbs full of water. The stand will be about 3 feet high and the base will be about 2 feet by 2 feet square give or take. I have minimal carpentry skills but am trying to teach myself.

The question is, what dimensions of lumber to use. I don't want to overbuild it, I could make a 2 x 4 frame that would probably hold over 1000 lbs. I want to use the narrowest wood that will do the job, for efficiency but also for lightness. Also what sort of design would hold a load the best?

I was thinking of a rectangular cage made of 2 x 2's (four vertical 2 x 2's one at each corner, with a square of 2 x 2's on the base and at the top) , with either plywood or 2 x 2 cross-bracing to keep the thing square, and a flat plywood square on top to distribute the load. I was thinking I would put this together with glue and wood screws.

Is there any hard data on what weight different dimensions of lumber will hold, and which frame design will hold the most weight?