Thanks guys, yes I've been looking at custom frames, Iolo and Leeson were two frames with hidden pipework and both look so much tidyer for it. I just though using solid lines would be less flexible than braided hose and potentially give a more solid/predictable feeling brake lever. I wouldn't dream of doing this on an aluminium frame, but then I wouldn't trust my lardy arse on a alu frame either. I'll have a look into M6 and 6 hydraulic fittings, as for the syringe thing, I would fit brakes that I couldn't bleed through by adding oil in the caliper and beeling it through the lines and through the caliper. I'm pretty sure I can get 1.5ish mm copper pipe, just need to check if I can get fittings on to it (they may need soldering) and a suitable method of attaching them to the frame.