sledgehammer has an Uno Turbo Kent cam' for sale. I have an X1/9 1500 head all you'll need is a pointless distributor and pair of webbers or bike carb's and you're away.
For gravel work I'd keep the suspension height standard and narrow tyres. I have a rear beam, arms, hubs and calipers from a Punto GT if you want to update the rear end or just fit the disc brakes. 4mm Pollycarbonate will fit the standard rubbers. If you want some wider wheels for tarmac I have a set on Phase I Uno Turbo 13 inch wheels, a set of 14 inch Punto Sporting and a set of 14 inch Punto GT wheels.