Hmm, ranger of elemental? Ranger or elemental? Or warrior?
I just want to deal insane ranged burst damage, so I'm thinking elemental. But it seems like switching between attunements is practically mandatory. Ranger sounds like a class that could deal some good ranged damage, but does it?
Warrior with a rifle or longbow can be pretty powerful, and both integrate well into several play styles. Might be worth considering.