Maggies for HT in medium size room?

Hi, moving to a smaller space and need advice on setting up HT with Magneplaners. Room would be 14'x17'. I've now got a 5.1 setup using SMG-a's in front flanking an 80" TV with MMC for center. Sub is a rebuilt Velodyne ULD-12 while small bookshelf speakers handle rear/surround. I've also several other speakers in storage - pair of refurbished MGIIIa's, KEF LS-50's, and old set of MB Quart 1's, so there's some stuff to play with.

My hope would be to cobble together a 7.1 setup by using the MGIIIa's in front and SMG's and LS-50's for side and rear. Those are the best speakers so first choice would be to use those. Another consideration is that the front speakers would also be used for a high end 2-channel audio system. [this was covered in another thread and elegantly solved. ]  Obviously that favors using the MGIIIa's in front as they are sublime IF positioned properly. So I envision a couple scenarios, such as.....

Case 1: build system around best speakers

1. Does it even make sense to use MGIIIa's in front? The sound best when well out from the wall, say 3-4', They'd certainly be less than that.
2. What to use for the sides? LS-50's or SMGa's? Seems like LS-50's would be less directional and "beamy" than SMG's. Also less obtrusive.
3. And what about the rear? I guess viewing couch would be pulled out from rear wall somewhat, but still not much space. That suggests LS-50's for the rear to conserve space. Then that puts the SMGa's on the side.

Case 2: Maybe more practical, easier placement

1. MGIIIa's in front, lose the SMGa's.
2. LS50's on sides and Quarts in rear (or vice versa)

Of course there are various further permutations and I'll certainly be listening to various possibilities. Still, finding the best starting point would be great. Any comments, ideas or suggestions would be very helpful. Cheers,