Any one know where to go for tuning bits for this engine?

It's found in ClioRs, 182 and 192.

Specifically looking for cams / Heads as pistons and rods are easy.

try prima racing at nottingham sorry havn't got there number anymore or have a look at www.hillpower.co.uk he has a good reputation and is reasonably priced located at measham or j11 m42 hope this helps