Good luck with it. I think you'll find it's more difficult than you think to get where you want to go, in order to end up with a unit you can build at a decent cost and reasonable time frame.

glass air channel,ceramic heating element,adjustable heat,no plastics
The Vapolution already has this setup, except they use nichrome wire instead of ceramic. And the heat source is outside of the vapor path. No screen either. At $150, The Vapo's hard to beat for an all glass vapor path.