I have the opportunity to upgrade my 30 gallon to either a 55 gallon plus stand for $100 or a 65 gallon plus stand and lights for $150. Right off the bat I know people will say the 55 gallon has a better footprint (because I think most people tend to prefer 55 and 75 gallons over other tanks) but when you do the math the surface area of the two are quite similar with the 55 gallon having 624 square inches of surface area and the 65 having 648 square inches of surface area, and then obviously the 65 is slightly taller at around 25 inches instead of 21 inches. So the 65 is a foot shorter than the 55 but is much deeper and does have more surface area overall with only a few extra inches of height. But the 55 gallon is a more standard size tank and would be easier to find parts for if I needed them for some reason. What do you guys recomend?