Recommendations and thoughts for end game speakers and amps

In regards to cables.  Tell the dealer you will use your existing cables, then call Iconoclast as they will offer a 30 day money back guarantee. I borrowed the Try cables from a local video dealer I purchased from to do the compare. Turned out to be a good move as I saved enough to help pay for a better dac. As for power cables, I think improvement is dependent upon your setup and the house/rooms electrical wiring. I plan to investigate/upgrade power cords last. 

You will love the 866 and the Rockports….sounds like you were at Soundings in Denver. (The Nordost recommendation). Hopefully you got the digital version of the 866, its quite amazing for the miniscule cost to upgrade. Its the best $20,000 solid state integrated amp in my opinion and it only costs $15,000! I’ve purchased three 866’s from Soundings and Jeff is outstanding. They are a fantastic dealer IMO.

The Rockports are exceptional as well. Ignore those telling you its foolish to spend this much….it isnt if you have it and enjoy music. Its highly likely they havent heard anything of this caliber or they wouldnt have said anything. Reach out to Boulder and ask about speaker cables….its actually the amp that is more particular about cables than speakers but you dont have to go crazy. I found the Tellurium Q Black to be a nice power cable for the 866. Its not that fussy, even a Shunyata would be nice. Boulder and exceptional power supplies are synonomous. Its a dead quiet amp.  Might I suggest that you shop used/certified Gen 5 pre owned Transparent speaker cables. Thats probably what is inside your Rockports.

You will love your new setup.

@ghasley  

It is Soundings in Denver. Jess has been really great to work with. I am getting the digital upgrade as I’ve read only good things about it. Thanks for the vote of confidence in my choice I’m really looking forward to hearing the set up in my room. 
@markc1961 

Thanks for the cable tips. I’ll use that approach 

The Marten Parkers trio are exceptional Loudspeakers
the Diamond edition even better still perfect match for theGryphon Diablo i have heard them both together and on the low side of your  budget.

Rockports are incredible.  There is nothing wrong with them as end-game speakers.  Boulder is brilliant with them.  I might also look at Constellation, Soulution and D'Agastino, but Boulder is safe and it is unlikely you will be disapointed.

There are a bunch of other awesome speakers in your price range.  Vivid G3s, Wilson Benesch ACT One Evolutions, etc... but they are not inherently better than Rockports.  Different and I might like their tech better but it is a matter of philosophy and taste.