I heard some sound stellar with some Wilson Watts. You might be able to get some cubs for 3K. The other choice ( I know I sound like a broken record), would be audio physic virgos.
Basically you want a high efficiency speaker with ruthless detail to take advantage of BAT's combination of relatively low power and high transparency. Thiels are too bright for my taste, but then again I've only heard them with older solid state. The merlins are supposed to be great for smaller voiced tube systems. Soundstage has an online review. I would look for a medium sized monitor/floorstanding dynamic cone speaker. Dynaudio's are also very articulate. You should be able to find a contour 3.0 or 3.3 in or near your price range.
Basically you want a high efficiency speaker with ruthless detail to take advantage of BAT's combination of relatively low power and high transparency. Thiels are too bright for my taste, but then again I've only heard them with older solid state. The merlins are supposed to be great for smaller voiced tube systems. Soundstage has an online review. I would look for a medium sized monitor/floorstanding dynamic cone speaker. Dynaudio's are also very articulate. You should be able to find a contour 3.0 or 3.3 in or near your price range.