A quality floorstander will normally handily beat a quality bookshelf+sub. For my main system I would not stray from the floors. I use the M3s in my 'gym' and M2s+sub for computer speakers and they are great, but if I had the space and money they'd be M80s all around! Unless, of course, you intend on moving them a lot. That could be a pain.
Not trying to push PSB/Para, but you can usually negotiate a more reasonable price from the dealers. I got My Monitor 11s cheaper than M60s, although the Signatures, at least, would still be in a completely different tax bracket (never looked into the PSBs).
