You should be able to pick up a motor off any old appliance, I find them mostly around garage sales and buy them for 5 dollars or so.
Keep your eyes peeled for anything that may be belt driven, usually they will still work, some may need a little bit of re-wiring, like a mains cord. If you don't know what you are doing there, then make sure that its someone who does know. It's not the hardest thing to fix up, but because they are usually 240 volts, safety is needed. Specialty bearing stores should be able to help you out with them if you are able to remove them from the unit.
If the shaft of the motor turns, it means that is not seized and should work again.
May I just ask, what is wrong with the current motor? I pick them up off hard rubbish after being soaked and dripping with rain, but after a quick clean, they usually will still work as long as the coil windings are fine. If you have a multi meter you can test for continuity to check the coils and connections.
If you want to test the motor out, make sure it is mega dry, plug it in, stand back and flick the switch on and off very quickly. If it makes a nasty buzzing noise, and sparks, it would need a bit of work. But most old motors will run.