I have not auditioned any of these amps with the speakers you own, but I do have experience with the amps driving other speakers. If I were buying (which is the only way I can answer your question), the Bryston would be the clear choice for me (I assume you are considering the 9B-ST for home theater use). The other two amps are fairly close in performance to each other, but I'd be inclined to get the B&K as my second choice and the Acurus as #3.
If you were considering the Aragon rather than the Acurus -- both are made by Mondial -- then the Aragon would be the clear #2 choice, very close to the Bryston. If you narrowed the choices to the Bryston 9B-ST versus Aragon's 5-channel HT amp, you definitely should do an in-home audition.
You did not indicate if you have considered one of the 5-channel Rotel amps. If not, you should. Personally, I prefer the Rotel HT amps to both the Acurus and the B&K, but others may disagree. I think that Rotel is offering very high value products in your apparent price range, and deserve your serious consideration.
If you were considering the Aragon rather than the Acurus -- both are made by Mondial -- then the Aragon would be the clear #2 choice, very close to the Bryston. If you narrowed the choices to the Bryston 9B-ST versus Aragon's 5-channel HT amp, you definitely should do an in-home audition.
You did not indicate if you have considered one of the 5-channel Rotel amps. If not, you should. Personally, I prefer the Rotel HT amps to both the Acurus and the B&K, but others may disagree. I think that Rotel is offering very high value products in your apparent price range, and deserve your serious consideration.