I would also probably use the 805Ds as fronts as they are a much better speaker than the CM's
Having CMs as front and 805D's as rears is a crazy mix
makes me really laugh though - stunning rears to have - the 805's are so transparent they would be an awesome rear lucky you
I would upgrade my amplification before buying any more higher up the chain B&W speakers mate
They require the finest amplification money can buy with a lot of current / power.
Get the amplification as high up the chain as you can afford / fit into your system, then look to add even more demands i.e. 804 to your system - that will be a stunning system no doubt though
804 D fronts with a HTM4 D centre then the 805D as rears - you will need proper power amps like bryston etc to get that system properly going. An AV amo is not going to get the best from them, nowhere near
However with a good acoustic room I doubt there is much better out there. different but I doubt much better without going silly