B&W speakers are very high quality. I bought a paid of 603 about ten years ago and have had no problems with them.
Granted I was using an Adcom PreAmp and Adcom Amp.
Last year I replaced the Adcom PreAmp with the Outlaw 950.
I have now sold all my Adcom and Outlaw gear and going to buy the 990/7125 combo (since it's $1K less than the 990/7700).
Even though your 800 series are 2-steps-up from the 600 series, I believe that would should very good using the 990/7500/7700.
But if you have alot of $$$ I'm sure you could spend more for a Decoder and Amp that would sound better.