I would choose 1 with a catch. You would have to hack/blow the staff door to even access the vault (which you would have to blow).
As soon you entered the staff area, you could get 3 stars (one guard with a pistol would be guardignt he staff door.
Then, after making your way downstairs, you would face 2 MP5 armed guards. Then, you could (finally) blow the vault and get its contents, and run all the way back, but you would get around 60-80% (or something) more cash than bank, but since it would take a long time to enter, crack 2 doors (etc) it would compensated for the bigger cut, as it would give plenty of time for the cops to come.