Asuming that great imaging is indeed what will satisfy (and that's NOT a given), you still have to make choices:
Minimonitors, whether alone (ProAc's Tablette is the best iamging mini I've heard) or coupled with a woofer cabinet (I own Parsifal's - also outstanding) can provide a particularly dramatic "object hanging in space" effect. Narrow baffle floorstanders with extreme cabinetry can also mimic this effect.
OTOH, Omnis like the MBLs (or, to a slightly lesser extent Ohms) can create "weightier" localized sources and a wall to wall soundfield that feels real in a different way.
Planars can create something in between, with more "continuous ambience" than minimmonitors and more specificity than most omnis.
I currently own examples of all 4 types (Maggie planars, Merlin VSM narrow floorstanders, Parsifal mnimonitors with separate bass cabinets, and Ohm omnis) and the imaging from each can -at any given time- seem more convincing than the others. At the moment, I'm sticking with the Ohms, but check back in a year....
Marty
PS I'd agree that, overall, MBLs are the most convincing imagers I've heard, but they have tonal issues that make them a difficult proposition for me (especially at their price).