Hey Dan, - For 2 channel only look to the M3v3, they will offer a fuller sound and is the best stand alone speaker. Of course, the addition of a subwoofer will provide a deeper bass presence and support the bass information provided by the M3.
Adding the center speaker will enhance vocal presence when watching movies or broadcast, if the viewing/listening is within 12 feet of the screen opt for the VP100, if further than 12 feet look to the VP150.
On placing the M3 to the cabinet you should have a least 2 inches of clearance for the rear port more is better and the speaker itself should be a 1/2 inch forward of the shelf it is sitting on for the speaker to disperse correctly.
The in-cabinet version would acctually be the M3 in-wall.
http://www.axiomaudio.com/m3-inwall-speakers.htmlCall me on the toll free number at 1.866.244.8796 if you have any further questions.
