If you're going to treat areas A & B as one room, a pair of LaScala/Belle/Cornwall would probably work very well. Area C is smaller, you'd probably want nothing larger than a Forte in there; a pair of Heresy might work nicely.
If you do come up with a pair of K-Horns for the bigger room, expect to have to build Mr. K's 'false corners' to support them with a proper corner.
I'm envious of your project, good luck!