Cambridge Audio Azure vs. NAD c320bee, c740

I need to replace my 20 year old Rotel receiver, which just stopped working. I have Mordaunt Short Pageant 2 speakers of the same age and a Rotel RCD950 CD player which is more recent. I also have Grado HP1000 headphones. I would like to spend under $400 and will consider pre-owned or refurbished units. I have narrowed down the choices to the NAD c320bee, cambridge audio Azur 640a or 540a integrated amps, or the NAD c740 receiver. Is the nad c320bee significantly better sounding than the c740? (if not, I would get the receiver to have the tuner capability). Are either/both cambridge amps better than the NADs? Finally, are the headphone capabilities significantly different between these models? Thank you in advance for your input.