Hi Ausfart,
I also own the B&W N804S and they have been driven by a Denon 3803 for audio plus I have a ISCAN DVDO VP20 by Anchor bay for video processing.
My Denon is rated 110W as 7.1 or 140W as stereo which is achieved by having the single power supply.
I can turn my amp up all the way where it is loud but not deafening and these speakers could use more power. I too am looking to swap out the amp but not to play louder just that I do not think the sound stage at moderate volume is all that great.
I have read all of the forums for months including NADt785, Denon 3,4 and 5 series, Onyko 906, Integra 9.9, Rotel, Outlaw, Marantz, Yamaha z7, Sherwood R972 (not out yet but interesting) and I have finally reached my own choice for pairing the 804
Emotiva XPA 5-2 - Toroidal transformer and 200W per channel, 5 yr transferable warranty, 30 day return for $699 and all the reviews, blogs are highly positive plus Made in the USA. I have not seen a 5 year transferable warranty and I think the company is putting product quality on the line.
Later I can add the XPA 2 at 250W with separate pwr supply, transformer to run LR if I go 7.1
OPPO Universal Blu-Ray, I will wait for review and product release in early 09 at $499. Oppo also USA and takes best components in industry to make all in 1 universal player for SACD, DVD-S and Blu-Ray. Cambridge Audio has the second most interesting CD player that upconverts the audio and most interesting read on their approach but pricey $1500.
EMOTIVA UMC-1 Video/audio processor $699 also not released but will be the successor to the MMC-1. Teaser Specs are on the Emotiva website.
Given the date on your post you may have already bit your bullet but if not I really think the Emotiva has got the quality and value concept in solid position. With the AMP and Processor your are getting 100 Pounds of Audio/Video and it really needs serious consideration. It is direct market sold and serviced only, so the price lifts are minimized.
These picks are going to put your cash outlay at $1900 without sacrificing quality, functionality, and power. You can pocket the rest except for the cables. I would read the Audioholics review of cables and it is beyond my expertise to get into that kind of scrap so I will defer on the cables. I am assuming you have a sub for your system.
Check it out!