You could mix and match with different preamp and power amp though it's a question of personal preference. Personally I would rather stick with the same manufacturer for both pre and power for synergy and/or compliance with technical specification.
Which pre should I choose?
I have an Accuphase A47 to drive my Dynaudio Coutour 1.3SE. I want to choose a pre-amp to match my power amp. and the speaker system. I prefer classical music. My room is not big. But I like warm and sound with thickness. Do you have good suggestion? How about Ayre's K1XE or Audio Research R2 MKII?