Most of us are in a similar situation as you in that we don’t have purpose built HT rooms and have to make some compromises. If you do plan on going with shelf placement I would stick with bookshelf speakers and not in/on wall. Bookshelf speakers can at least be repositioned more easily allowing you to experiment a bit with placement before putting up the shelves. Also a I thing you suspected bookshelf speakers are likely to have less problem being placed close to a wall because they have less bass extension to be reinforced than tower speakers will. If you did chose bookshelf speakers I would go with the M22s.
