FYI if you want to have them vent right through to the engine bay, you will actually have to cut metal out of your fender too. If you take these off, there's solid metal behind them.
There's a DIY thread somewhere in the DIY forum where a guy did it. I was considering doing this too (I HATE fake vents), but it seems like a LOT of work.
Good luck on your search!
*EDIT* found the thread:
http://www.ft86club.com/forums/showthread.php?t=70815