B&W 803 D3 speakers - which amp?


I just upgraded my speakers to B&W 803’s and currently have a Mcintosh MC207 powering them for 2 channel music and 5 channel home theater...sound is quite good from the MC207. The question is...how much difference will it make if I switch to a 2 channel amp like the MC462?
mluters
He has a used MC452 for sale that I can take home and try for 2 weeks and the MC462 is at his showroom
Hello,

i have similar arrangement but I do not think I am getting the best of the speakers.
I have 4 x b&w 803 d3 + centre and currently all this is run by Arcam 850

could you please suggest how to improve sound ?
Would it be a good idea to buy Classé 5300 and then look for another processor ? Can I use my old Arcam and add the Classé as an amplifier only ? 
Maybe it is possible to add powerful stereo amp to fronts and adjust Arcam to only rear and centre ?

Any advice would be appreciated

tom