These are plans for a tank I want to build for my 90..it takes a bit more wood working skill
http://www.arbreptiles.com/cages/75g_stand/index.shtml
Just adjust tme materials for the size tank you have.
This is a basic one you find al over the net,however I dislike it for large tanks because the stress is places on screws rather than letting the wood handle most of it..
http://www.garf.org/stand.html