Funny how you think 6 to 8 weeks is plenty of time. /forums/images/graemlins/blush.gif
That's a huge pad and it's gonna take some serious skills to get a pad that large level. Putting in the forms is another big job. Are you doing these things yourself?
How deep do your footings need to be? What sized rebar and what spacing. Tying rebar will take a full day, maybe two.
Is your ground hard? Digging your utilities can be a nightmare in hard packed clay!! My building is half the size of yours and it took me several days just to get the drains dug and installed. Of course, that was seven bathrooms, five washers and three sinks!! /forums/images/graemlins/grin.gif
Get on it today and when the material arrives, you should have a nice solid pad waiting on them that is dried and cured.
Have fun,
Eddie