One vote for Mikalor and two against, three including myself. Keep 'em coming. Thanks for the tip on the bolts Si, I'll get the better grade if I go that route.
Rather embarrassingly I was looking for the wrong clamps yesterday, when I said 'standard' I was thinking of U clamps. Below is what I should be using.

I've even two of the three needed in stock which fortunately were in the same bag as the rubber hangers. I can use stainless bolts with these so that solves most of the problem of U clamps. Stagonset seem to have gone tits-up which is a bit of a pain.
These folk have the correct length (2 3/4"), Namrick and most others only do half inch increments.
Shiney shiney

GEX are still going strong but the guarantee is still useless though because their terms require that you return the registration card. I got the zorst 2nd hand so don't have that. No matter, I plan to well and truly void the warranty on the downpipe by fitting a boss for a lambda probe.