That Mk1 Fiesta is a great looking thing.

I'd also look at Mk6 Escort RS2000 or an RS1600i (Both go on ebay for way less than £5K). Don't know there bhp/tonne but maybe spend the change on upping the power?

Fiesta RS would be on my list to.

How about a Fiat Coupe turbo? Pug 306 gti?