Moose Hunting Newbie - need advice

Doing my first fly in self guided moose hunt, what kind of call should i get, I hear the electronic calls are the best thing out there? can you please provide some knowledge for me.

Also are hip waiters a good idea?

I recently bought a foldable chair, and a nice bog death grip bi-pod.

I currently only a 270, is this caliber too small? should i invest in a 300 mag