integrated or separates...on a $1200 price point?

The DK integrated are a hybrid and give you the solid state slam with a tube preamp built into one package. A great bargain used.

Separates give you flexibility in mixing and matching while integrateds give you simplicity and convenience in a one-box. The main advantage of separates is when huge power-hungry speakers are used and huge amount of power is required to drive these speakers. That is where massive and heavy power amps and monoblocks come into the equation. If your speakers are efficient and relatively easy to drive, I would say integrateds are the way to go. There are many good quality integrateds these days that can give you comparable if not better performance compared to separates.

With the B&W 685, I would think that a good integrated might fit your needs better if simplicity of a one-box is important to you. Not only you save space for an additional piece of equipment in the preamp but you save on an additional pair of interconnect and power cord.

Adcom GFP 750 pre-amp and a Musical Fidelity A3cr dual mono amp. Both Stereophile class A at one time (I'm 90% sure). Used you should be able to come close to $1200.

Consider Yamaha A-S1000 or a used A-S2000.  Really refined and with exceptional build quality.  I used to have a Musical Fidelity A3.5.  It was not bad sounding but the parts quality was mediocre at best.  Jamicon caps and such.