Speakers--Epos? Spendor? ATC? What?

All--

I'd appreciate your thoughts on speaker choice. I think they're the hardest to select because they show the most difference on a quick dem, and because they interact with the room more than other pieces of a system. I'll be moving shortly and the room the system will be in will be fairly large--20'x17' or so, with a concrete floor and the speakers along an exterior wall.

System is currently a CDX, LP12/Geddon/Ittok/Troika, Kairn, 250, and SBLs. I've also got a beat up pair of Linn Nexus. I'd like to find something that retains most of the strength of the SBLs while also adding others, like spatial separation and tonal color. As you'd imagine, something with good bass definition is a must, as is tune playing ability. They also need to be available, and be supported, in the US. Music is varied.

So far the speakers that would seem to fit are used Epos ES14s, Spendors (1/2, 2/3, and maybe the 3/1--not sure if it goes low enough), and ProAc Response 2. Budget is limited to around $1200 USD or so, which is around 700 UKP (I think).

Comments on the speakers I've listed welcomed--as are suggestions for others (ATC 12?, etc.)

As you can probably tell, I'm a pretty committed "Flat Earther" who values tunefulness etc. above imaging/staging/etc. So more typical "round earth" speakers probably won't work.

Best,

Bob