I shoot stock service pistol with my Glock 30 with no problems. There is no "bullet" shape requirement. Shoot what will function reliably in the gun, and won't bother your pre-existing injures.
As long as your rounds meet the minimum power factor for the division you shoot in you'll be fine(125 for Stock Service Pistol, Enhanced Service Pistol, & Stock Service Revolver; 165 for Custom Defensive Pistol). You will need mag carriers. If you can't get hold of any before the match, go anyway! Someone there will let you borrow some. For a better idea of the IDPA rules check out
www.idpa.com. Remember, HAVE FUN