Thanks for the replies guys, Ive had a look artound and it may come to buying some grade 2 S95 jackets. think I'll call/email point north first though.
On the other hand I had this bizarre idea about making my own from some 2mm thick black plastic I have lying around, though getting them all the same size would be the biggest challenge.
I'd need around 12 -14 buttons, I planning a ventile Smock based on a modified Falklands cold weather parka, similar to the sas windproof smock.
Andy