Build you own watermaker parts

[geem]

Can anybody help with a supplier for watermaker parts in the UK? There seems to be lots of companies that will supply you with a complete watermaker but none selling the parts to build your own.
The main part I need to source is a membrane pressure vessel. I already have a CAT pump and motor

 

[npf1]

www.desal.co.uk

 

[dougg]

+1 desal supplies for the membrane.
Pheonix for the pressure vessel.
E bay for the chemicals
Good chandlers for the rest