[banditpowdercoat]

Welcome, and would love to see pics.

Tank wise, I would go with the 48". As it's wider and taller. Much easier to aquascape, and lighting should be cheaper, although need more wattage to penatrate the depth. I think the skinny tanks lend themselves more to FW applications, as the fish can easilly swim through the plants and such. But, in SW, the rock takes up a large part of the tank.