They're Recaro SPG's, the cheapest place I could find them from was sportseats4u.co.uk, but Mark Fish got them ever so slightly cheaper for me, which was nice of him!
The harnesses were very expensive (around £160 each) - but they are so easy to adjust it justifies the cost (well, to me anyway!). Edit - and yes they are FIA approved.
Thanks all for the positive comments!