I enjoyed the Ayre V-3 (no longer in production so you would have to buy used) with the B&W N804 and the Ayre AX-7e integrated with the B&W 804S in setups I've owned. Either of those (the AX-7e can be used purely as an amp) or a used V-5xe would be a good fit.
What amp for B&W 804?
I presently have Mcintosh MC7270 with a Prima Luna Prologue 3 pre amp. I traded my prima luna amp for the Mac thinking I was taking a step up. Not so. My present system sounds strident and thin in the mid range. It doesn't have the rich sonics that i expected. I have been told by an audiophile (I'm a amateur) that the Mac is not the amp for the B&W's. My question: What amp does fit the B&W's? Say in a price range of $3 to $4 thousand. I am not anxious to spend money, but I sorely want a stereo system that is a plessute to listen to. The Prima was good but not great. Jnorth