In reply to JayPee630:
Thanks everyone for your help so far.
So basically, it looks like I'm looking for an unlined windshell (lightweight softshell).
People have mentioned the Rab Boreas, however has anyone found the non-helmet compatible hood a problem?
The only windshell I can find with a helmet compatible hood is the Rab Alpine jacket, however pertex equilibrium is not completely windproof and it bobbles after a bit of wear.
I'm also looking at other things such as the Rab Cirrus, Montane Shark/Mountain Star/Lite-Speed but I'm not sure whether they'd stand up to the rigors of rock/alpine climbing (they look like they're designed more for trail running) and also lack a helmet compatible hood. The Arc'teryx Squamish hoodie looks good but is expensive.
If the durability is a concern with Pertex and similar fabrics, it brings me back full circle to things like the Rab Boreas and Zephyr jacket.
Thanks for taking the time to read my long/slightly confusing post,
BR