Are you looking for plans for a metal stand or a wooden stand? Don't know of any for a metal stand, but when my dad and I build wood ones this is what we do.

Find two trees where you want a stand about 6-7 feet apart. Use 2 2x8 treated timber and nail them between the trees (one on either side) Then use treated 2x6 and lay planks for the flooring on top of the 2x8's. Cut the 2x6's so there is about 12-14 inches of over hang on either side of the beams. Floor the entire space between the trees and then go and buy a ladder from a garage sale, paint it, and put it up. For chairs we use those white plastiv deck chairs. We just paint them first. This has worked very well for us and it is fairly simple to put one up in a couple of hours. Just make sure you have permission to build perminant stands first.