Why spend the money on a smaller tank just to upgrade to a 75 later?
true, and might I suggest getting the 90g over the 75.
you get a larger volume and nicer looking tank, while only spending a few extra dollars on the tank alone. foot print is the same.
all the equipment for a 75 and a 90g are the same...
so its well worth it to go with a 90 over the 75.