WC71N is a Maplin motor about the righe speed to drive a drum directly
WC70M is a faster motor from the same range which would drive a roller to sit a drum on.
Both of these are suited for 12 volt operation so can be left to run for hours off a car battery down the garden. Both are brush motors so there is a need for care and a good case to keep dust out of the motor.
Search
http://rswww.com for parvalux and you find hundreds of motors in the 20 - 200 watt range with gearboxes for anything from 0.5rpm to 200rpm from single phase ac mains. Look through these for a motor that suits then look for TEFC then look for the gearbox style and ratio that suits your need.
Buy the Maplin motor if this will be a short term hobby or the parvalux motor if this will be along term need.
Parvalux do have a number of agents round the country who stock motors and gearboxes and will assemble whatever you want at a price. (parvalux.co.uk) They do not sell direct in singles!