The pipe is indeed metric but also narrows to a 10mm male thread.you should be albe to buy these pipes in a fexli version as opposed to copper. If your really stuck buy a cheap set of monobloc kitchen taps (€35) most of them come with what you need.
Do you know if Heat Merchants store these? I looked through their catalogue on www.heatmerchants.ie but couldn't find what I was looking for. Don't want to waste a journey to their stores if they don't stock these.