I would probably suggest a waterjet because the amount of money in Argon you will spend will probably justify the expense of the waterjet.
For starters it will be hard to pierce the material and since you can't pierce it with oxygen (it usually explodes and leaves a crater instead of a pierce hole)it will be extremely difficult to cut it.
Difficult, not impossible, unless your lead in comes off the edge of the sheet. Keep in mind that this will require a lot of pressure (18 bars) and volume. Also, it will be extremely slow depending on the laser power of your machine.
Good luck