I'm i've been looking at the Onkyo DS494 receiver. It is rated at 55 Watts X 5. Will this be enough power to run a pair of M3Ti's (and possibly a VP100 center channel and surrounds) in a medium-sized room? I'm not interested in being able to play at ear-splitting volumes, but I would like to put out a decent amount of sound every once in a while.

Also, as a general rule, how high can you run a mid-level amp like an Onkyo before you get clipping and damage your speakers?