Just search for pin collar shirt on UK ebay, there is a fair selection on there, including several with club/double round style collars and a few arrow pointed collars, the last time I looked. They mostly have contrasting collar/cuffs though, not many without, so depends on what you are looking for. Not the greatest quality shirts, obviously for £20-£25, but the one I have fits well and seems pretty well made/stitched. I'm sure they'll ship worldwide, have just checked one and they do. I'm pretty sure some of Jermyn St. Shirtmakers do them too, but I'm not sure which ones, as I don't like any of their collars (Pretty sure T.M. Lewin is one though). As for collar bars, I've finally managed to get one from ebay. They seem to be almost unheard of in the UK, where collar pin seems to be the only option.