New metal prep

[bikerdad46]

I am new here and to PCing (haven't even bought my gun yet). I was talking to gentleman the other day about some solar heaters he had in the back of his truck that he builds. And Powder coating came up and he said he would love to find some one to PC for him. I told him that I was thinking about starting to PC myself and he said great. That maybe I could start up and do PCing for him.
The metal will be in the neighborhood of 16 gauge sheet metal (steel) PC flat black.
My question is. Will I need to sandblast the parts or use a dip to prep the metal for PCing? Which would be the faster prep.
How much coverage do you get out of a pound of powder?

I am going to start PCing no matter what. But the deal with this gentleman will dictate which gun I buy. If I make the deal, (sort of a production line) I will probably buy something like the Hypersmooth. If not I will buy something the hotcoat dual volt gun or the caswell gun. I am limited on space (12 X 20) and budget. I can build nearly anything with my hands. So a lot of my equipment I will build myself.
The oven I haven't decided on yet (electric or propane) or the size. I have got to get with him and see what size the panels will be, before I build the oven.
Any and All advice will be helpfull
Thanks
Ray "bikerdad46"