My personal recommendation is to consider some other solid state amp than the B&K. B&K uses MOSFET transistors in the output stage, which tends to make them sound rather warm and soft. A better idea, IMO, would be a SS amp that uses bipolar output transistors. Most of the top SS amps use J-FET transistors in the input stage (very linear for low level signals), MOSFETS in the gain stage, and bi-polar transistors in the output stage. In the systems I've heard that use a tube preamp and a SS power amp, the SS amps with bipolar output transistors have tended to sound best -- better bass control, better dynamics, and more transparent.
My comments are not intended in any way of "slamming" the B&K product line -- they make some excellent gear. If you intend to keep your tube preamp (which may be a good idea), then I'd make the switch to another power amp.