it all depends which route you want to go down, how much money you have and so on..
there are companys such as bahn brenner which do supercharger kits and so on.
idealy if you are using a standard engine as a base then you want to strengthen it first, this can cost you between £500 - £1000
for rods and pistons.
then youre gonna need different engine management, cheapest route is megasquirt.. not a bad system if you ask me.
you could just drop a G60 in, but in my opinion thats just boring.