In my opinion go with the M60s for HT and the M50s for music. Try to decide which you tend more to use the system for or what your personal preferences are for listening.
The M60s seem to have a more clear (and sometimes bright) high end while the M50s have a more laid back sound (not as bright for music high frequencies). **according to some postings and my own opinion**
But overall i've found that the centre channel is just a nice addition to the HT system. It adds a more fluent movement of sound from right to left channels easing the imaging issues with speaker placment and hence is not 100% necessary if you have good speaker placement to begin with. So the VP150 should only be considered if you have a larger room and need the extra large sound. If you have a smaller space, the VP100 should be perfectly fine.
Again, in my opinion...
