Ahh I see, in the end this was the best price I could find for 6mm od x M8, there listed as 1/8 but if you message the seller first he'll send you the M8x1, I know you don't need them but others may and this is mostly for Jazz if he's interested in buying them cheaper.

Free shipping HIGH QUALITY 30pcs 6mm to 1/8" Pneumatic Connectors male straight one-touch fittings BSPT PC6-01

http://s.aliexpress.com/qiqMv2eY

I've ordered a smaller pack of 10 for £2.70 :).

.Me