Re: suspension, you don't want stiff springs unless you're running slicks - some compliance is a good thing, particularly at places like Cadwell/Oulton/Spa/Ring.
AST kit is mega, as is Bilstein. I'd also have a good look at Nitron's custom work. If you're serious about having a kit made up specific to your car and needs by an industry expert, I know a guy.
Oh, and feck me that's quick. I'm looking forward to the R-off at Inters.