I finished the installation today. Under the draws worked great. Everything works as advertised. I never went through the duct, just a small pilot hole, easy to fix.
Now for Lug_nut. I've never seen the Newmar Option unit. Can't say if its good or not, but knowing Newmar it's probably a nice unit (may even be a Dirt Devil.
For Obi-Wan Kenobi. The Power Head was included with the unit I purchased. Try RVupgrades.com thats were we got ours. I think they carry the power head separately.
Thanks to all for the help.