Geoff, Being in the biz "Home automation, and home audio", I would have to say what you are trying to do would probably be a bad idea. PC's are not good for what you want to do. Otherwise we'd be selling them by the boatload. If you want whole house audio for a decent price, check out Nile...
Crestron and housebot are two very different worlds. Housebot may or may not be able to control you B&O system. The reason I say it may not be able to, is B&O uses a higher IR frequency that is not as common as other manufacturers. I have seen some IR repeating equipment act up when sending ...