Buy a second car, its easier. I bought a rolling shell off a mate. I got another complete car with mot for £2000. Sold the rolling shell from the second car for £1200 once i had all the bits for my original sapph. Its a cheaper way of doing it. If you buy bits individually, ie engine, turbo, etc etc, it will cost a lot more IMO. A cheap donor car is the route i went down. The car finished, stood me around £5000, that was a full underside restoration, and engine rebuild.