Unlike my gentle, politically correct friend Fangar, I will say more bluntly that if you were to pay Harbor Freight $329 (on sale) or $399 regular price for their "Powder coating oven", you would be wasting your money!
Several have already said, "heat is Heat!" - and most of us "users" have pretty well done the same thing and that is, headed for the "thrift shop" and paid $10-$25 for a used toaster oven - works perfectly BUT, get the tallest model you can find (none are very tall) because as you transfer your powder-coated pieces from your spray area to the oven, hopefully, you'll not have to experience banging your parts jig against the opening of the oven and watch all (or much of) your powder fall to the floor of the oven (off your parts). If so however, just take it out and blow all the powder off wuth your air hose - re apply powder and try it again.
I did look for a larger, taller easily available toaster oven - actually a little more than that with a grill, rotisserie, bun warmer, etc. that you can't really use. It's a George Foreman toaster-oven, available at Sears and other places, I'm sure, but it's $89 new - BUT is is about twice the height of your normal T-O's.
And that's the news as I see it.
Jay
Oh!!! FANGAR - who does your metal engraving on the brass casings?
Thank you,
Jay