I imagine its a posh knocking shop, a bit of gambling, with escort girls in attendance, pole dancing and an expensive bar and 'rooms' for hire.
For the hens I reckon it will be much the same with Chippendales or the like serving the drinks. Hopefully not a cake where the star hunk pops out for the bride to be to show her what she's missing (tacky). As cazz says it will no doubt be expensive.