The bigger the better no really if its a basement setup go for an inwall setup as it is cleaner look,do custom tank as long as you like a feature wall giving yourself a back work room totally insulated and vented.Do maybe 30" wide and I don't suggest going over 30" deep unless you have long arms
maybe 8 feet long X30"X30" roughly 375glns
or 8feet X30"H X 36"W roughly 450glns
So many choices
now I want a bigger setup