No single style covers all the bases well.
Best thing is to learn various styles.
Things to consider:
Nearly all street fights end up on the ground so get some good grappling experience (ju jitsu, wrestling).
A large yet determined man can cross a room in less than a second (even over furniture), probably faster than you can draw your CCW, aim and shoot. Based on your question, I assume you realize that wearing your gun isn't a magic force field that automatically repels all attackers. You may not have time to draw.
Learn a variety of basic weapons also. Stick, staff, knife as well as your gun. Learning the basics of how to use them not only teaches YOU how to use them, it teaches you how to DEFEND against them if your attacker has one.
Learn how to defend against multiple attackers. Jackals usually travel in packs.
Learning various styles teaches you not only their strengths (grappling, hand-strikes, holds, kicks, throws, etc.) but also their weaknesses.
Best bet, get a mix of bare hand styles (Ju jitsu, judo, kenpo, taekwondo, boxing, wrestling) and mix in some basic weapons training (stick, knife).