Best integrated for B&W 704 and Rega Apollo

I'm searching for a new integrated amp for my B&W 704s, hoping to stay around $11500 used. I'm soon to get a Rega Apollo CD player. Don't yet have a turntable. I tried a Sim I-5, loved the quickness and detail. (I thought it was remarkable in how each instrument in the music retained its own tonal quality. It's been my experience that even amps that are reputed to be neutral rather seem to discolor the music and make it sound grey.) But I also thought the I-5 was too bright and underpowered for my speakers. I need good power for low-volume listening, not high volumen. Auditioned the new Bryston 100ST, found it to be thin. Am thinking about a Musical Fidelity A308 but I can't audition it because I can't find anyone in my area who has it. I like that it's reputed to sound tube-ish, but if it's like the newer MF A3.5 or A5 then I'm afraid it will sound too sluggish and have poor imaging.

I'm basically looking for something that has the quickness, if not the great detail, of the Sim, but also sounds full and warm, and has power. Any ideas?

Thanks, R