Celtic Heroes

Many quests require you to kill harder mobs (also bosses) which you would need a group to fight unless you are way above their level, it's much more fun (at least for me) to do them as the quest gives them and not have to wait and level up a ton. But as for gear, especially as a druid the shadow armour is actually pretty good, arguably better than warden and meteoric, and you can get those solo without too much difficulty, other players might even give you some drops and make it go faster. There are 3 tiers, dusk, dark and spirit, they give focus and a skill but less armour, which doesn't really make much of a difference as a druid or mage ime. With that gear and doing the quests you should be able to get to 140, maybe a little higher with no real issues. (thought it will be slower and a little harder to get gear.)