Thinking of an 'easy' upgrade - advice on tank and stand wanted

[Slick Fork]

Hi there.

So, I'm starting to get the itch to upgrade into something a little more substantial than the 33 gallon display I have going now. I have most of the ingredients for a moderately bigger system (lights, skimmer, sump, etc.) except for the actual display tank itself. I'd probably need a couple of powerheads or a wavebox but otherwise I think I have everything.

The stand I have is 47" X 20", welded steel courtesy of the Grizz. When thinking of a foot print for this new tank, would I be alright in looking at a 48"x24" footprint provided I put a substantial piece of Plywood under it (like 1/2" or 3/4" thick)? I'd imagine it would be OK, but would like other opinions. Currently it's holding up the 33 display with the big sump underneath. Grizz, if you read this and felt like commenting on the capacity of this stand to handle a larger tank I'd appreciate it.

Anybody have any tips on evaluating used tanks? I've had two large used tanks in the past and bought them without a lot of consideration and was lucky on both counts. Looking at adds on Kijiji though, you start to get spooked wondering things like, has it ever had copper or been dropped, or had a pane blow out and been improperly repaired, etc.