Your best bet when hunting as a pair is to try and choose two trees within a few yards if each other to setup. This will allow you to communicate better. Setting up further away is okay, only if you have some years in the turkey woods and really know how the other person thinks. My brother and I have used that tactic many times, but we've been turkey hunting together for over 20 years.

I don't hunt out of a blind (too restrictive for me) but you would probably be better off sharing a pop up blind.

Definitely get a slate call. Slate is easier to get good sound on and needs less care than glass, crystal, or aluminum. Learning how to hold the call and the striker properly will go a long way to helping you call in a bird. Good luck.