Thanks, I've sent you a dm, I'll check that link out too. Brexit sux :(
Hopefully getting some samples of CLO insulation, looks a lot easier to sew into clothes than the Apex Climashield I've used for quilts.
Not going to be anything too advanced, just a bum and a thigh panel (sewn in like a shirt yoke), with a pull cord for legs. Main priority is warm and lightweight.