These seem heavy duty. Instead of a butterfly, it has a sliding gate. I've seen one in person and they seem well built, but kind of big if you have clearance problems.

http://www.jegs.com/webapp/wcs/store...0002_359170_-1

 

I've been told that "Doug's headers" electric cut-out is really good, have one on order but have no real world experience. Memeber on here recommended it.

 

another vote for Dougs... they are nice

 

I have an electric 3" cutout from Badlanzhpe.inc with remote control. It's worked really good. It can be opened from the switch or from the remote, one click and it opens or closes all the way (no overtorque problems). It can also be opened and stopped at any position.