if its Turbo power your after, then like AKRS1 said, fit S2 RST engine and 'box, if your just after a bit more poke, then the mk5 XR 1.8 zetec 130bhp will provide a big improvement over the 1.4, if you get a complete donor car, you can fit almost everything, from engine to suspension/brakes, and interior, this works out as a cheap conversion, if you do the work yourself, a mk5 XR3 thats had a rear end shunt won't cost much