Congratulations - that is a big step up indeed. I've used the Sophia 2s for many years now with a B&W Matrix HTM center channel and find the voicing to meld pretty seamlessly. I think you'll be pleased with how they integrate. The Bose 101s? Not sure they're a real match, but hey, it's only HT right? They're all 4 ohms so you shouldn't have any real issues unless the sensitivity is a real mismatch (affecting volume).
Have fun listening!
Have fun listening!