Just had a reply from James, he says go for a Nitron or a Maxton shock over a re-valve. He is keeping his eye out for anything second hand, but says they don't come up often.
Nitron and doing some good deals at the mo advertised in the Bike mags. You can upgrade to remote preload adjustment for half price as well at the mo. BTW Demon Tweeks are an approved Nitron Dealer, give Andy O a ring and see what he can do! (I better be on ya Christmas Card List Andy!)
Demon Tweeks are an approved Nitron Dealer YT, just in case you missed my above edit! Drop Andy an email