I spent a couple hours on Skype with him talking about the feeling for the music to convey as well as sound effects. Music will probably come first, as that might help shape the game. Sound effects aren't planned until we have specific things (models/animations/events) where sound would be specifically appropriate.
Check out his site: http://chriskukla.com/music/orchestral.html - A lot of his music from Orchestral to 8 bit. I've listened to most of it, and am quite pleased with the skill and ability involved in each peace. A few pieces I felt where close to the game already but not quite. Industrial Horror was a good one. Perhaps a little too dark for this WW City, but not for WW Strategy. Chill was another good one, not quite what I would use either, but I felt that both had certain characteristics fitting to my current idea of the game.
No idea when, but I can't wait to hear some of the experimentals/ideas he comes up with.