Dont even attempt this, It wont work. Regardless of the fact the guy may have put the best pieces in his home, It wasnt meant to accomodate that sort of weight. If you do, Set up a video camera, make sure its running first, and afterwards send the tape to Americas Funniest Home Videos, to help pay the contractor, that you will need to fix everything.

To add to what Ruby said:
Think in terms of a frozen lake, and someone went thru the ice... If you attempt to walk out to save them, you are in the drink too.. Because your weight is being beared in each step by a small space, say 3 inches by 8 - 10 inches... to save the other person, you need to Lie on the ice, spread your wieght over a broader area and reduce the LBS per Square inch...

The same applies here, you are going to attempt to suspend yourself from a small attachment point.. Unless the bolts hardend, and driven into the joists, preferably all the way thru, with a nut on top..