Mr. H your room seems pretty decently sized as well as far as i saw in the photos.
My cinema room is about 10 foot wide and 18 foot long ish.
The MB2's are about as large as you could get in a 5.2 ch system.
PMC's are very deep in size, I would like to see a "Tall" version, I think that would suit more rooms - But might not be acoustically practical.
My comment was comparing my own room to James' set up above.
Wierd how people read things in different ways - My comment was on its own and not related to your post. My poor use of English usually does not help !!!