I'm working on the Revotec range at work now. They are now distributing Comex fans, which are very good. I discovered on their website that are getting rid of their former range which was already good material, and brake the prices. £30 for a 12'' fan, that is a bargain
http://www.revotec.com/acatalog/General-Cab-Fans.html
Perhaps it can be useful to some of you, so I thought I could share the info.