I've never heard of heat injection.
You do need a special printer, it's called a plotter.
http://www.signwarehouse.com/specials/
It's basically a printer with a razor blade on the end that cuts your design to spec, then you peel away the outer area. You'll need to outsource it.
This guy:
http://tearstone.com/shop/
Is a member here and a stand up guy, and does great vinyl work.