Taking my first test EVER in a WEEK! YIKES! HELP!

ok, first of all, sorry for the overdramatic title.

I just interviewed for a corporate communications company. I have 2 fellow smoker buddies who work there already. From what I hear, I will get a call in about 4-7 business days with an offer, and at that time, I have 2 days to pass a drug screen.
I have been smoking heavily for about 7 years now, and DON'T KNOW WHAT TO DO. I NEED this job. They both told me to use Quick Tabs (found at the vitamin world at my local mall). They both used it, smoking the DAY before the test, and had no problem.

BUT, I smoke more often than them, for much longer, and I weigh more than 200 Lbs, and they do not.

Does anybody have any first hand experience with either Quick Tabs, or this specific scenario? ANY help at all would be greatly appreciated! I'm going to stop smoking tonight, and drink as much water as possible, but I'm already pissing clear. AND, I just bought a few home tests, and may have some hospital tests coming from a friend of mine.