Know there are many of these but I wanted to document my own and get some advice along the way.
I bought the steel from lowes.
Used a miter saw with a metal blade to cut the steel.
Put it together using a thread on here, I didn't use the steel plates in the corners yet (I sat on it and moved around with no problems so I might not)
Found a easy and cheap low pressure manifold that I liked on here.
Waiting on parts/money now, I'll updated as I go.