First thing they need is a full water analysis and they need to do it before any water filters. Have them get it done by a local certified laboratory.DONT HAVE A WATER TREATMENT COMPANY TEST THE WATER.Once they get the report back from the lab, they can start calling around to get quotes and opinions on water treatment. The proper way to treat iron bacteria is by a chemical feeder that injects bleach into the water. After the chemical feed the water would go through a carbon back wash filter, and then a water softener. They would need a contact retention tank but in the past i have gotten away with a static mixer. I treated 32 ppm iron with that same method and the system has been working fine for 4 years but i think the carbon filter is due for a re-bed soon.