I am using Von Schweikert VR2s with my MA6900 adn they work very well together and the VR's are fantastic for the price if you can find some second hand. Good luck!
Ive owned the the 6800, fantastic intergrated at 150 watts with autoformers. However I 100% agree with Zoya about the speakers. You have a very nice system and will be blown away by another pair of speakers. Good luck!
Yep that's the stuff, I have a MX134,MC352 and MC7205. I am sure there's better or at least to all the non-Mc dealers. But you can't beat the build quality, style and service you get from Mc. Congrats, I'll bet it sounds great