I always found imaging was more a function of the speakers. I've been a planar guy for a long time now, first with Apogees and now with Maggies. I'm not familiar with your particular speakers so I can't really comment there.
Not my cup of tea, but the Black Ice Audio F360 has a soundstage expander function built in. Not sure how it does that but it might be an option while keeping your amp.
Not my cup of tea, but the Black Ice Audio F360 has a soundstage expander function built in. Not sure how it does that but it might be an option while keeping your amp.