No, I wouldn't advise you to look for bookshelf speakers that can be wall-mounted. If anything, that should be worse than on-wall speakers. As for driver sizes, well, that depends on how loud you listen. If you only listen at modest levels, 3" woofers like the revels ought to be fine. If you want something that is more fun, I would be looking at 5" to 6" drivers. The mostly subwoofers only handle deep bass, ie. 80 Hz and below, but most of the bass range is actually handled by the speakers, so bass playback will suffer if you get speakers that have mediocre headroom in bass frequencies.