Integrated or Separates?

This is my new 2-channel system that will only have the basics: CD source, Pre/Amp and speakers. Speakers, so far, will be pre-owned Proac Response 2.5's. Speaker cable currently is Monster Reference Z2 with spades. Source will be a quality CD in the $1500-$2000 range (used GamuT, Naim, Cary, Arcam, etc.). IC's yet to be determined. For Pre/Amp, a couple local dealers are pushing integrated amps (i.e., Plinius 8200 MK2) as the solution unless, in one dealer's words, you're going to spend $6000 on the Pre/Amp combo. My budget is only $2000-2500 for Pre/Amp new or used. Do you agree that a "quality" integrated makes sense for this system and budget? If not, what would you suggest? Music is jazz, classical, soft rock and voice. Room is 15'x17'x8' and open on two sides (living room). Thanks so much for your thoughts.