Dominic,
We use a Warhammer variant, derived from the set of Warhammer Fantasy rules, which were published in Wargames Illustrated a while back. We are still working on our set, so many ideas are just scribbled notes here and there, or even in our heads! I don't like sets like The Sword & the Flame much, but may buy the reprint of Science Vs Pluck, as I like Howard Whitehouse's approach to games.
David