I agree with Rob if response is all you want i would save your money and not worry about internals or head work. I am making 170kw atw with a vf10, all with similar mods to what Rob listed.
i currently have 17" semi slicks on the front and it still smokes them up through all of second and bit of 3rd. Its fun to start wit but trust me you get over it when you cant get traction.
If you have plans of going bigger turbo down the track which will happen i garentee, id probably do the botom end now so you dont have to worry bout it later. but in the end it is really up to how much you want to spend and what u want the car to do.
check out this link
http://www.astinagt.com/forums/vbpic...p?do=view&g=67