Energy makes a great product, and I think their C-series is superior to the Paradigm Monitors so I think you are on the right track. I would rank the C-series between Paradigm Monitors and their high end Studio series (that's the conclusion I reached when I shopped both brands last year)
I would, however, go with something from SVS or Hsu if you can. The Energy 10.3 is very good, but it will be outperformed by the Hsu/SVS speakers at similar price. With normal speakers, it's important to match brands/models, but with subs, you have a lot more freedom to choose. An SVS PB-10 would work really well with either system and provide superior but tight bass in your medium sized space.
One other thing, I would actually choose the Energy C-C3 center channel over the C-C1, it's a much superior speaker. If that eats into your budget, then choose the C-7 instead of the C-9. Since the majority of the information comes out of the center speaker, you don't want to skimp there. Energy itself says the C-C3 should be paired with the larger floorstanding models.
