RUN! CHELBY RUN!!
Seriously...If I were you I'd just stick with your food and cake/goodies plan..run out and rent or buy a couple of those "action" movies the kids like at that age...go on-line to find some silly 6 year old games to play....then...
sit back...enjoy.... and watch to see kids...especially 6 year old boys...can still have fun w/o big blow up jumping toys!
Oh...and NO JUMPING off the couch!