New Class A/B under $6K, your recommendation?

Okay I'm tiring of my class D amps and have upgradeitis. I want to try a latest greatest Class A/B amp - I'm thinking Benchmark AHB2, or Son of Ampzilla, or?
 I can drive it with a Manley 300B pre, or a Wyred 4 Sound pre, or directly from my Benchmark DAC into big BG Radia 600 speakers that are rated up to 400 watts. They are line array types using BG planar magnetic drivers - intended for wall mounting, but after hearing them and speaking with a BG engineer, I built beautiful boxes for them according to specs and have been grinning ever since.
 I spoke with Rory from Benchmark and he suggested that 1 amp - even though rated at 100 watts per channel would suffice. I could always order a second and use them bridged and be at the upper end of my budget.
 Any thoughts on what else I should be looking at? I'm looking for: Imaging, space, neutral sound (not cold, not lush and warm) - I can color with my pre if I should so desire. Thanks for your input!!