The M60's are very good on their own, so don't think that you would be compromising. Now I've only compared them to M22's and other brands and have yet to hear the M80's. I like you're idea of ordering both and letting us know what you think.
With regards to the VP100 or VP150, I'd recommend the 100 for your room. I've now owned both and the VP100 is more that capable for the room size you have.
In your future, no matter what you buy I'd put money on it that you will get a sub. Nobody ever stops.
2 ---> 2.1 ---> 5.1 ---> 5.2 ---> 7.2 ---> 9.4 --->11.4
