You have to look at what a crate thief needs to do to get all their goodies. I'd say the biggest thing is to get the goodies.
120 stealing
How do you get to the goodies with the fewest skill points?
100 hiding
80 stealth
How will you be getting to said artifact location?
Magery or Chivalry come to mind.
Now, once you reveal yourself, you might get targetted by the mean ole monsters then you have a range of skills to look at.
Ninja for smoke bombs, animal form.
Healing could use a variety of skills: Heal, anatomy, spirit speak, chivalry, magery, magic resist.
Beyond that, you really need to know what you will do in the dungeons. If it's merely getting loot maybe throw in some detect, lockpick and remove trap (if on Siege). If you want to kill monsters or other players, there are other routes to go. To be honest, I love template building, but there are too many questions that need to be answered before you can get too indepth.
At this point, all I will suggest is that you have 120 stealing so you don't fail on 10 stone items. Everything elese is up to your own game play...la