Speakers for BAT VK 75SE

Slightly more money than the speakers you listed, but Vandersteen's new Quatro may be a possibility for you.

I used to have a pair on Audio Physic Virgos with a BAT vk60. (I have a vk75se now). Same size room as yours. I listen to the same music...loved those Virgo's. Not sure your budget...but used they are around $2500.

The most important thing (imo) for matching speakers with the VK 75SE is to find a speaker with a relatively stable impedance. Since the amp uses no negative feedback, it does have a pretty high output impedance. The more flat the impedance, the more flat the amp's frequency response.