I just whipped the crane arm together at work, not much to it just a flat plate 6"x30" 3/8" thick. Then I welded the 2x2 tubing through it for the hinge, then the arm sticks out about 5'. I used 3/8" thick plate for the gusset and machined the angle on it. The hoist is from Princess Auto (Canadian) rated at 330lbs.
As for the ceiling it is 3/4" insulation board with the reflection side out. I couldn't afford to put steel on the ceiling yet so I went with this for now and when I'm ready for steel I can just go over top. I will be using a tube heater so the reflector side should help alot.
The floor was treated with Super Diamond Clear.