Your best bet would be a set of Kef Ref 1 as they are remarkable sounding and have adjustable bass ports so you tune the speakers output. You don't need to worry about the rear port as the cabinet's size is big enough and you can absorb of any reflected engery, some wool batting mounted inside the cabinet on all sides would do nicely to eliminate any internal reflections, acoustical solutions makes this material.
The Uni Q driver allows for a very wide soundstage and is also a very coherent sounding driver, we would recommend that you install a small wooden lip made by using a 1 * 2 on the front bottom of the cabinet which will keep the speakers from sliding out and then use one of two sets of isoacoustics footers on the back of the speakers or use another 2 * 4 with a set of isoacoustics footers on the rear to raise up the back of the cabinet and angle it down, the front lip 1 * 2 is being used to secure the speaker even with the angle and you would be good to go.
Adding a high quality in ceiing sub would be great, although the Ref 1 have fantastic bass.
A point source is the only kind of driver that will work well in this application. Also adding a preamp with room correction will also help.
You can PM us for more info.
Good luck.
Dave and Troy
Audio Doctor NJ Kef dealers