dont know what size you are looking for exactly...but I do have some visionariums that are the size of a 20 gal long. I like them a lot...have corns and beardies in them, they look awesome, easy to assemble. you can get them at lllreptile.com
if u want something bigger then I think the website
www.Dragons4You.net can help you out for sure.
these cages stack themselves... if ur wanting to build something to stack your own cages, then maybe a frame made of 2 x 4's would be a suggestion...someone else might have something easier