Good amp for B&W 804S for the space-constrained

Good morning folks. I've recently purchased a pair of B&W 804S speakers and need to upgrade my electronics (Denon AV Receiver) to get the most of their sound. Unfortunately the shelves I can use are somewhat shallow. Thus, I'm looking for a solid amplification system that will fit in, let's say no more than 16" including space for the interconnects. Not an easy task, unfortunately. Some ideas I've had (and even demo'd to some extent):

Naim NAIT XS (or maybe even SuperNAIT)
Simaudio Moon i3.3
Rotel RB1552 + pre?

Anything else I should be looking at? Has anyone had experience with any of these in combination with B&W 804S?