as far as Yamaha & Denon I prefer Denon because from my experience it gives my B&Ws a very pleasing yet dynamic in its range. However my favorite shop I go to for my B&W needs, there is a guy there who absolutely loves Yamaha with B&W. Its his favorite! So it really is gonna be up to you. The way I see it...Denon & B&W are both a "warmer" sounding product. Yamaha is going to be a little "brighter" if you will. So you may want to combine a bright&warm combo so it levels things out & you get the best of both worlds!...?
Oh the questions & concerns we bother ourselves with right?
Remember too...the speakers you choos are going to make the biggest difference. The reciever not as much. It will have a slight sound signature but not a major on once calibrated correctly!!!