I think I've decided on Tales of Argosa
Earlier this week, I debated on using ToA or WWN, and while I'm still a little unsure, I do think ToA fits my imagined setting better.
The general idea is that a supernatural apocalypse occurs merging several worlds together, introducing fantasy creatures and magic into our world. Naturally, that doesn't go to well, and after a bit, the modern world sort of falls to ruin, partially because now magic weilding elves are fighting for land, but also, nuking dragons doesn't end well. A few hundred years after the fall of the modern world is when my setting takes place. Everything has regressed to a medieval style of living it's the new dark ages. Guns in some form still exist, although they are rare, and the knowledge of how to make them is a closely guarded secret to the rare individual who knows how to construct one.
I have more ideas detailed as I've been working on this setting off and on for a while but was unsure of what system would be the best fit.
All of this is a byproduct of you guys giving me solid advice on both systems.