125 is all youd need, lol all i think ive ever use has been 125 hp and sp so im not so sure on which is better but as far as going out to over 20 yards the 125 hasnt failed me yet although i used some s&b 158 sp when i bought my newest toy, and other than the reviews and bad cycling of my pistol due to power residue it seemed fine but i also was not trying to record muzzle velocity or anything due to my lack of equipment and excitment of my new piece. but overall i wouldnt think anything about them stacking up against one another unless your planning on doing some long range pistol shooting in a competition setting where all that will definately play a big factor. but for personal defense id suggest the 125 as it will undoubtably be faster for the close range that will be expected in this scenerio. plus if your using hollow points the 125 would spread better and use full potential of the hp factor but these are my views on it. hope it helps your decision.