Welcome, Hockey. You've started a fight on your first post!
I don't have much to contribute beyond saying "welcome" and asking how big is your room / how loud do you listen / what type of media are you planning on enjoying?
The reason I can't contribute much is that I've only heard the VP150 and I have the VP160 on my "next purchase" list. It's designed to be the best match to the M60s.
It's a little large, though (necessarily) and not an inexpensive Center if you're on a tight budget. And, frankly, if you watch Chick Flicks more often than action movies, the difference between a VP100 and a VP160 may not matter as much to you as it does others.
If you have the room for a VP160, but not the budget...skip it for now and set your receiver to a "phantom center" as mentioned above. You can add it later.
Another option that many here prefer is using a traditional (i.e., vertical) speaker for a center channel, but many can't fit that option. And, personally, I would probably lean towards an M22 for a match with the M60s... and that's the largest "traditional" bookshelf speaker to place.
Have I helped yet?
