Need help designing metal stand

[Ruckus16]

I'm working on a frag tank build. 48x24x10
My brother-in-law is a welder at a fabrication shop and said he could build me a stand for the cost of the metal. I'm wanting to build the stand the same dimensions of the tank and put a piece of 3/4" plywood on top.
I don't know much about metal, what size tubing should I use? Can I leave a full 48" span in the front without a center brace?

 

[Ruckus16]

Thinking something like this without the feet

 

[thewbell]

Here is mine for a 5' 120. I used 2x2x.120 and C4x5.4 channel because I had it available but it is overkill. You could easily get away without the channel on a 4' stand and I hear most people use 1.5" square tubing instead of 2". Personally, I like working with .120 wall as it is easy to weld and a good balance of strength, weight and price but I know many people use thinner wall and it works out fine as well.