a research or krell pre amp for krell ksa-150 amp?

i am looking to buy a pre amp for my krell KSA-150. i have been planning on buying a krell used in the $800.00 price range. i noticed AR were signifigantly less expensive and from what i have read, seem to pair well with krell amps. is there a pre amp that is known for this combo? i listen to all kinds of music from jazz,R&B to rock. i definately need slam but i also want warmth and detail. what is the best way to accomplish this?

please advise