The company I got the heater from is called Carlton Technologies ( carltontech.co.uk) but that said when the unit came it was sent direct from Spain and contained the invoice to Carlton and what a markup,

but I can provide you with the Spanish company who sent the Heat Stick only thing is not sure if they will deal with Joe public but worth a try, It cost me £40 plus postage with Carlton the invoice from the Spanish company was 24 Euros for stick and to include the shipping

.
http://www.cartridge-heater.com = Spanish company give it a go, look at the Stock heading on the left.
Oh re: the Control unit you should see inside it, some one made this unit with love

, the internal loom is held together with surgeon like ties( wire) the chap I got this off of says this would have been £1,000+ when new.