I was considering building a stand for a new 75 gallon tank and I've got a
few questions. I'm not so concerned about the support, as I am about making
it look pretty and doing it economically. I'd hate to pay a bundlee for the
wood and have it look like crap. I've done some woodworking, but no
cabinetry. So your cabinetry advice would be appreciated.

Most of the designs I've seen have a top and bottom frame made out of 2*4s,
sitting on top of 2*4s for support. The problem with this is that they don't
have a bottom shelf like a kitchen cabinet. I was thinking of removing the
bottom frame and rabbeting the legs so they could be joined front to back,
rather than side to side. This would distribute the weight across the floor,
not just on the pots. I would then attach this to a plywood base (3/4) to
distribute the weight across the floor. This is similar to my prebuilt
stand, except that it's made out of MDF and not 2*4s.

I was also going to notch the support posts and set the top frame into this,
so that the top frame had better protection against racking. But would this
weaken the support of the top frame too much?

Finally, what's the best way to face the front? How do I go about concealing
the 2*4s behind the doors? I could cover it with plywood (veneer) and cut
door holes, but that seems pricey. I was thinking about using 1*4 pine to do
this, but I'm not sure if it would look funny against the stained venner?