The P360 is a pretty nifty option, given that it comes with a low staple indicator that tells you when you're almost out of ammunition ... tweak the setting of the staples for a better finish.

This stapler holds a full strip of 210 staples. A helpful low-staple indicator lets you know when it's time for a refill. SECURES 40 SHEETS – Strong stapler fastens up to 40 sheets of paper.