Hey Rack, you'll figure it out and I'm sure you'll end up with what you want/need...
I recently ordered a 270WSM, I was also looking at the 300WSM and 325WSM. More of an intuition/impulse thing ordering the 270WSM, because I really liked the option of shooting 180's with the 300/325WSM's. My 270 shortmag will mainly be for sheep, but also elk and deer, maybe the odd moose.
If you want the option of using 180gr bullets, go with the 30 cal, otherwise the 270 WSM, even with smaller lead, will get the job done on any animal in Alberta.