May be doable in a day with a mate or 2 but its a big job if you haven't done it before. Pulling the dump, turbo and manifold off took me a few hours, you've still got the intake manifold, coils, plugs and rocker to come off before you even start on the head.
Can you garage it until you get the box done at CMS? Get it trucked down there and have it all done at once if you can, $$ wise its probably the best move.