For mouldmaking and casting material, very near school:
http://www.tiranti.co.uk/
And for some finishing, (also there are lot of radios control):
http://www.hobbystores.co.uk/
And also, CNC material, finishing, moulding...:
http://www.4rfv.co.uk/outside.asp?id=14306&to=www.ambercomposites.co.uk&cat=289