want some guidance for a whole house iron remover

[iscewedup]

Hi, I have well water system with a 2 ppm iron. my water softener does a good job of taking care of the iron but I still have the sulfur (rotten egg) smell. Im looking at iron removers, I see some that have potassium permagranite and others don't. and some say air injection. what should I be looking for in iron removers

 

[Reach4]

As a gating factor, how many gpm can you deliver to the iron filter during a 10 minute backwash?