Erron's core tools (the ones you mostly use anyway) are a mixed bag of full screen, mid screen and up close and they are all very good tools at that. Fortunately he retains all of them regardless of variation, so pick one that emphasises the game plan you prefer:
Do you want extra pressure/rushdown? Pick Outlaw
Do you want extra zoning synergy? Pick Gunslinger
Do you want 2 more powerful (but slower start-up) zoning tools and combo extenders? Pick Marksman.
Erron only gains from his variations, he doesn't lose a thing so there's absolutely no con to using whichever you want. Picked outlaw for extra rush down? Don't worry, you can still zone effectively with his low hitting, knockdown on hit, sand grenade. Picked Gunslinger for extra zoning? Don't worry, you can still pressure with F122, b3 , sand trap etc.