My personal advice is to go with a 3' high stand or lower (if you are not at least 6'2").
I have a couple of reasons for this.
1) Most corals look better from a slight view down aspect, especially acros, if they are placed above the eye line they are not nearly as attractive.
2) Having 4' of depth is great for aquascaping, and logically the highest points will be toward the rear of the tank. However if the tank is above eyeline, your depth perception will be cut as the forground will dominate. You will be able to see through to the back, but not across through to the top. Consequently the 12" topmost part at the back of the tank will be lost from view.
3) Maintainence. Speaks for itself.
Good luck, look forward to it