The guides on ww2airsoft.org.uk are quite handy for WW2 loadouts. There are also lots of WW2 games listed in the forums.
I would suggest that you start with Battledress for a British loadout with P37 webbing and then customise from there. Commando would then have a woollen hat green beret or brodie helmet and may swap the tunic for a jumper or Denison smock. Windproofs were issued mainly to mountain troops and may have been used by Commandos but only late in the war and if you want to get into WW2 airsoft that limits you.