It sounds like your priorities (as are mine) are music first, HT 2nd. Some have mentioned that two channel is not as good as multichannel for HT and I agree. However, Linkage mentioned that he was interested in the Belles because of the HT bypass.
For those who might not know, this allows you to use your front two channels from a stand alone two channel system and use them for your HT as well. You get the best of both worlds.
Out of those you mentioned the Belles are in a different league from the rest IMO. I have heard the Belles Soloist-3 with a Belles 350A, Naim CD5 and Usher speakers and it was awesome. The Belles have a true to life sound that is hard to match at any price.
To me the Soloist-3 is a no brainer, but I'm not sure I'd go with the Soloist amps. You can get a used Belles 150A hot rod for about the same price as a new Soloist, or a Odyssey Stratos even. I owned the Outlaw Model-755 and in it's price range it has no peer IMO, but it's not a Belles either.
I have the Belles 350A Reference and an Arcam AVP-700 pre-processor which I use in by-pass mode for music. This processor is known for its musical abilities, but it doesn't come close to the baby Belles. I'm going to get either the Soloist-3 or the Belles 21A.
It looks like your upgrade path almost mirrors mine. I recently bought a pair of Usher CP-6381's and they are superb. I was using Energy Veritas 2.3is' and to my ears the Ushers have a more clear and detalied midrange and and better bass extension.
However, I'm not at all sure I like these better, as the Energy's are just a really nice all around performer as well and excell with dynamic capabilities the ushers cant match.
For HT the value of Outlaw is hard to deny, especially their amps. However, I've owned many Adcom components over the years and am a fan of their equipment as well. Tough call.
Feel free to email me if you would like to discuss further.
_________________________
Zu Druid Mark IV, Zu center, Sonance TR-4000, SVS 20-39PCi, Sony DVP NS999ES, Arcam AVP-700, Outlaw model-7500.