Most will tell you that the 'monitor' lable is of higher procduction quality than say just the standard or cinema series. Then steps up again in the 'Refrence' series and so on.
this is actually a useful link for you to brouse.
I've used monitors from many different brands, but for movies...there is no substitute for a floor standing full range speaker! None! I plan to eventually have the same BP 7004s all around......some day.
I think those monitors would be an outstanding addition. And seeing that the center you picked has the basic same driver complement, you really cant go wrong.
Be forewarned though, you wont want to leave the house for awhile, so make sure its stocked!