POP 3 Ho-Oh ex is a duplicate of the UF one - it just has different art (so when Unseen Forces rotates out next year, the UF Ho-Oh ex will stay legal until POP 3 rotates out, which won't be until 2008).
You can see the scans for all the POP cards at pokegym.net, but I don't know if you have to register for their forums to do so.