Firstly you will need to get the block bored if needed, or checked, then u can order some low comp pistons to the size u need,

i brought the Ross racing forged low comp pistons £500, P.T.S,
You may want steel rods. very expensive, i didnt bother coz of the price
ARP bolt set
Re-ground crank
New oil pump (£70), i put a new sump on while it was out aswell (£35)
Gasket set (geniune ford are best) expensive though, about 80 quid with crankshaft carrier