6 year old boy party. Bouncy castle or magician/entertainer?

[Phoenix]

He wants a pirate theme party and I've found a few pirate bouncy castles but I'm just wondering if an entertainer would be better.

If we went with the bouncy castle would we also need a dj? or would a cd player with party songs do? Would we need games or just let them go mad on the bouncy castle for an hour?

I've never done a childrens party before (can you tell ) so any help much appreciated :)

bouncy castle - they need and want to run off steam.
no dj neccessary, cd player with party songs will be fine.
for my ds (will be 5 soon) we will have a treasure hunt in the local park. with a treasure chest with the party bags in at the end to find.

Thank you :). I like the treasure chest idea.