There is a large selection of can and coreless motors on ebay. I have the 13mm X 20mm, coreless, 7 pole with 1.5mm shaft. Beautiful motor. There is also a double shaft version available. There is a 8mm X 10mm X 20mm long with gearhead, plus 1.5mm shaft. I have bought from this guy a couple times.
stores.ebay.com/microlocomotion
Rich