I'm mainly a sword person, but in most games where you can have two weapons I usually carry a close combat weapon (high dps) and a range weapon I can at least do some dmg while I'm getting in range of using my close combat (if they survive long enough for me to get close). I like it one shot with high dmg, don't need to deal out a high rate of fire. I was planning on going for either Iron Slugger or Callahan, but the Magnus is not quite what I expected when I planned out all my equipment.
I'm thinking maybe valiance is the way to go for me?
If you're only going to have one gun, the Valiance line is they way to go. Normal damage against all monster families, fairly long range, the bullets are large enough to hit multiple enemies fairly often, a decent charge attack, and you don't sacrifice much mobility when you just have to backpedal while shooting.