No harm in installing the stage III however it will be way more bite than you need and won't be as smooth as stock. That's the sacrifice you make for a stronger clutch clamp. As for tips on installing it, have someone else do it. It's a PIA. About 11 hours if you know what you are doing. Subframe has to come down and three of the 4 motor mounts have to be undone so you can angle the drive train to get it out. Make sure your slave cylinder is good or else you will be going through this again. When you are done be sure to bleed the clutch well and have extra brake fluid handy as you will likely go through a lot of it.
