Why not try the Benchmark as the pre for now and just put the investment in a good amp?
I almost went this route recently to go with my Musical Fidelity A3CR amp, which can be had used for well under $1000 and is quite good (Stereophile class A I believe) IMHO, but opted for a tube DAC rather than the Benchmark, in which case I would have gone with the pre model.
Then add a pre-amp upgrade later if you still feel the need.
BEtween the Bel Canto or NAD, I could go either way depending on the rest of the system. In general, and specifically given your criteria, I'd probably tend to lean towards Bel Canto.
I almost went this route recently to go with my Musical Fidelity A3CR amp, which can be had used for well under $1000 and is quite good (Stereophile class A I believe) IMHO, but opted for a tube DAC rather than the Benchmark, in which case I would have gone with the pre model.
Then add a pre-amp upgrade later if you still feel the need.
BEtween the Bel Canto or NAD, I could go either way depending on the rest of the system. In general, and specifically given your criteria, I'd probably tend to lean towards Bel Canto.