This is true, the curriculum has been set up so that the students basically make their own 4th year schedule. There is an online database containing hospitals and preceptors that have some sort of agreement with Western, and its fairly extensive. Unfortunately, you cannot view it unless you are a current student. I can assure you however that it is quite robust (nationally and internationally).
The fact that Western does not have its own hospital does not really impact the ability of graduating students to land their top choice residency. Same goes for universities with their own teaching hospitals, it just doesn't matter.
If you want to see the match trend for the past classes, you can check out the match lists. I think the previous poster started a C/O 2011 thread with links to the most recent years' match lists. Obviously this won't be able to indicate whether or not graduates received their first choice, etc... but you can see what people are matching into and where. Also note that trends change from year to year. Some years may be FP heavy, while others are IM heavy, Surgery heavy, etc...
Lastly, don't worry about residency; you won't have trouble landing one coming from COMP.