I have a full surround of Paradigms... I am very happy with, sound is outstanding. Go with the bigger center channel... you won't regret it.
As far as surrounds, I have a 6.2 setup with Studio 20's for my sides, and I bought a single ADP for my rear surround, which is spectacular, and fills in the small amount of rear channel sound that you need... there is an extremely small amount of movies that are truly recorded in 6.1 DD, and even a smaller amount recorded in 7.1, so IMO you don't need to dump a ton of money in the rear surround as opposed to the side surround, which is much more important.
If possible you can save some money by doing a 6.1 instead of 7.1.
I really like direct radiating speakers for side surround, but it also depends on your room layout.... with mine my screen is in a corner and rear surround is in a corner. Either way, I think a single ADP in the rear can serve quite well, if you can get your hands on just one....