The oven used for powder coating shouldn't be used for food because of the fumes and emissions as the powder cures.
I have a larger 6 slice toaster oven that I bought from Kmart for $40 for the powder coating system from
Eastwood (auto restoration supplier). This is identical to the Sears one and you can use powders from either one. If I had the space I would get an old electric kitchen range. Getting a used kitchen range is cheaper than a powder coating oven. Whatever oven you use must be electric and not gas. You need 400 - 450 degrees for the powder to cure, the higher spike in tempature during the first several minutes of cooking to "flow" the powder out. The size of the oven dictates how big of parts you can do.
Generally the darker the powder the more fumes it releases as it cures. Once the parts cool off from the oven they are ready to be used. They look as if they are painted, it's not a very thick coating, but it's much more durable than paint. The powder is sprayed on from a special gun using an electrostatic charge to hold it to the part. Any powder overspray can be swept or vacuumed up. The trick is to not touch the part after you spray it. Thin metal wire works good for this. After being coated you can carry the part to the oven and hook it onto one of the racks so it can hang freely in the oven as it's baked.