Here's a post I made last summer, where I superimposed the footprints of a couple of buildings (the Jobing.com Arena in Glendale and the UConn Football stadium in Hartford) over a few different locations to see how well they could accommodate an arena and stadium.
http://forum.calgarypuck.com/showthr...49#post3824949
I won't quote the whole thing (you can read it if you want), but here are the images:
1. East Victoria Park
2. Fire Park
3. West Village -- Greyhound Depot and GSL Chev-City
3. West Village -- Greyhound, GSL, Renfrew Chrysler
These are really the only locations that would be large enough; are potentially available for (re)development; and meet the "downtown" criteria. Firepark is not directly downtown, but its proximity to Deerfoot, Memorial, and the CTrain make it still easily accessible from downtown.