If you have access to D&D insider, issue 200 of dungeon has the adventure Blood Money, where the players have to plan a way to treasure hoard from a warlord's castle. Even if you're not using 4e, has some good ideas for how to run a caper adventure that are independent the standard mechanics. Looks like dndclassics.com has dungeon up to 198, so it will probably be available there too in a few weeks.