These are plastic kits which include underframes etc. & bogies (where needed). You will need wheels/bearings, transfers, couplings & paint to complete the kits.
Cambrian recommend Alan Gibson or Romford (Jackson) wheels. Avoid "RTR" types such as Hornby or Bachmann as these may be larger than the kit is designed for — this could make fitting couplings difficult, particularly on shorter wagons; also the axle length may also be shorter than the recommended makes' standard axles.