Originally Posted by cutthroatkid
... should I insulate&add a fan also how hard will it be to transfer the heating element&controls from a kitchen oven into my project?
You have already been studying the home built ovens on the web so you are on the right track. I didn't build my own oven, but have done similar research to yours and intend to build my own in the future so I can coat larger pieces.
From what I've seen the insulation is VERY important...and the more the better. And from my own experience, I would say the fan is much less important, or not necessary at all unless you are getting into a quasi commercial operation.
Most of the home made units on the web will show how they mounted the coils and the controls. But if you are concerned about that, I've also seen some that use an entire "hot plate" type electric burner, which would require almost no wiring of your own. The other option I've seen done is to use a typical kitchen range and then build and insulated box which extends right out the front door of the oven. This configuration does have it's problems (uneven heat flow and difficulty loading your parts) but it has been done.
All in all I think you would be best off finding one of the better constructed home made units on the web and then following that example as closely as you can.