Quick follow up.
A visit to my LBS today met with a final decision being made. The guy who runs the shop has 30 years of experience of wheel building and is well used by local groups. The clincher was that he only changes parts and doesn't charge for the build or for fitting. So new wheel set now ordered, looks like they will come in under 1500g, and can't wait to get them fitted in the next couple of weeks.
A big thanks to RRSODL. Our private chat gave me the confidence to go down this road, and hopefully other forum members will be in a position to use your services as I came so close to doing myself.
