@capt57 I would look seriously at the Supernait or a Uniti Star or Nova with a major caveat that they are out-of-stock. The absolute power rating isn't that high but it is plenty of power to drive those 805s and tonally is warmer and a brilliant match. The only issue is that they are out-of-stock at the distributor. The Uniti Star looks like inventory may be in soonish. The Supernait has no estimated delivery date.
An alternative at $6299, the AVM CS 2.3 is an all-in-one streaming unit that would definitely do the job. AVM is tonally quite warm and a brilliant match for B&W. This new unit has been worked on a long time to make sure that it is virtually bug free. My guys at the distributor have been running it for a few months without issue and have been super happy with the software. Silver and Black are in-stock and it would be a nice option for you as it has similar features to the M33 or the Uniti Star.
If I can think of something else I will mention it here.
@patrickdowns The Mu-So is in-stock at the distributor in three colors. It is a nice unit. I feel it is MUCH better than a Sonos or a Pulse but has the natural limitations of a single box. If you can live with that, it is a good sounding option.