I would suggest staying at 78. This is because at lvl 78, you can do PT, BFR and FT (PT is more common like ciega said). at lvl 72, your lightning reactions will give +15% movement speed, which you dont have at lvl 70. This helps tremendously with dungeons. On top of that, you could use the 75 pvp set. for gear, use 75 pvp set, or 70 sprite set. Weapons, yellow bodor sword, purple sword/another bodor sword, and for guns get a bahado gun (or the orange version too if you wanna proc 2 guns). You dont really need a purple gun, but its always nice to have one.