PF track is basically 9-volt track with the metal conducting rails replaced with solid plastic. They clip seamlessly together. However, there is a large market for straight 9-volt tracks so you could recover part of your expenses by selling them and replacing them with PF-tracks.
The train shed was designed for 6-stud wide trains, so most of the official LEGO trains will fit, no problem. However, the Emerald Night is the exception because it is 7-studs wide at the cab and 8-studs wide at the running gear. Looks like that locomotive will have to sleep outside... That being said the 10027 train shed is a great kit, one of my favorites (I only wish I had bought multipules) so you shouldn't let the fact that the Emerald Night doesn't fit keep you from getting it. Its price on the second-hand market could be another thing...
Sorry about that comment. I did not write that part, some malicious hacker is at work. I cannot edit my original post.
Haha, that's all right mate. Thanks for the response.