Goto Eastwoodtools.com and caswel plating. They have forums where people talk about doing it themselves.
I picked an oven out of the trash. Used some scrap sheet metal from airducts to make a box off the back of the oven. A wheel is too long to fit in a standard oven.
I hang the rack off a some 2 x 4's extending the saw horses I had. This allows me to hang the parts off the oven rack and powder them. Then put them in the oven for some baking.
The oven control costs about $100 to buy new. So that is a show stopper.
You will find plans and concepts for building various ovens in the forums.
The problem is the cheap guns are not the best and the expensive guns are very pricey.
I have a lower cost gun and do an ok job. It is not hard to learn and nice to not have to deal with solvents.