Cornucopia had some roman style pots that worked well for several of my renders (Scaled them rather large)
here's a plain terracotta pot: http://www.chromesphere.com/3dmodels.html
A few fancier ones: http://www.3dcommune.com/3d/freeview.mv?3DC_Model_Bank+yNigOyNPp+1142028602
Lots of them out there, just look for OBJ or 3DS files.

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