yeah a lot less of a head fook if you just drop a turbo motor in!
i've seen a lot of people comming into workshops getting their car turboed and a month later end up in the workshop again! going by the list nightcrawler posted, that should be the minium to make the mechanical side run properly, and then there's the brakes, suspension, clutch etc etc to make the car cope! it'll end up costing you a bit that's for sure