The sub looks to be self powered so no concern there. The first question you need to answer is if you like the 685s enough to keep them. If yes, then almost any decent integrated stereo amp should yield a significant improvement over your AVR. The Outlaw should work fine and is a good amp for the money, but it's not up to the standards of the Hegel IMHO (or probably the Krell either, but I'm not familiar with that unit).
If you're upgrading the speakers, wait until you figure out which ones before upgrading your amp so you make sure they work well together. A lot of people like Audio Note speakers, but they're quite different from B&Ws and there are lots of other great options out there. Hope this didn't just confuse things further.
If you're upgrading the speakers, wait until you figure out which ones before upgrading your amp so you make sure they work well together. A lot of people like Audio Note speakers, but they're quite different from B&Ws and there are lots of other great options out there. Hope this didn't just confuse things further.