DIY tank stand for 2 30" tanks....some questions

I am going to have my grandfather build me a tank stand for 2 30" tanks. He can build me whatever I want, I just have to tell/show him what I want it to look like.

My problem is finding some examples of DIY stands. I know it won't be hard to build, but I want to make sure its going to support the 29g on the top. Most tank stands built have the center pieces of wood in the middle (if you are looking at the front or back) which I assume is not only for support, but to make doors for the front and attach plywood when you finish it.

Since I want the stand to be for 2 tanks (20L on the bottom), I don't want that middle piece.

My plan is to have him build the stand 31" long to have an extra 1/2" on each side. And also, instead of having a single 2x4 for each of the 4 "legs", I want to have 2 2x4's (or 4x4's) like a corner for the for legs/corners, screwed together with angle brackets (hopefully the drawing illustrates it better).

Here's my sad MSPaint drawing: http://i4.photobucket.com/albums/y130/SouthernGirl8504/1standdesign.jpg.

Would this be a sturdy way to build the stand? The inside length has to be 30" as well so that the 20L will fit underneath. I will put a piece of plywood on the top and bottom for extra support.

Any thoughts, concerns, or tips?

Thanks!

Would I be better off using 4x4s? I know it would be sturdier of course, but would it be a bad idea to use 2x4s? My dad has some 2x4s here, so just wondering if I could use those.

Its trying to save it as a Paint Shop pro photo file, which is a program I don't have. So, I can't see it.

Can you save the picture to something like Photobucket and then post the IMG link or just a direct link to it?

Doh! I removed that program and it let me see the picture. Guess since thats one of the few picture programs I have, it was trying to use it even though my trial expired awhile ago. Didn't think about that earlier....