Well, I'm glad you asked because I have alot of experience with your situation. I live in North Carolina and have all my life. I did live in a small town up until 3 years ago. The water there was OK but we did have a softener installed by Rainsoft and all was OK. Until my wife saw an awesome piece of property in the same county and we did end up buying it. We wondered why it hadn't sold after being on the market over 2 years. That is until we saw what the toilets, sinks, etc. looked like. Everything was orange! We had the softener transferred thinking it would help, as they can with small amounts of iron. It was no match for the problem we were having. I know there are lots of options out there, but we had a Rainsoft technician come out, test the water and make a few recommendations. Our average iron level is 2-3 ppm, and it does fluctuate depending on how much water is used daily, rainwater, etc. We also had low PH levels, being around 5.8. However, the hardness was relatively low, around 3ppm. He said we could go with an iron filter and a PH neutralizer, but they have their limits and may not be able to handle larger amounts of iron. The 2nd option was a chemical injection system in which there is a retention tank (120 gallons), 2 chemical pumps and tanks, a Hysulex carbon filter, our softener and a large household filter. The first pump injects alum (aluminum sulfate) which is a floculant and that pulls all heavy particulates out of the water. They drop to the bottom of the retention tank and are flushed out. The 2nd pump injects caustic soda which raises the PH and helps clarify the water. It also injects chlorine to disinfect the water and is mandatory in NC with this type of system. All chemicals are food grade and all residual amounts are removed with the Hysulex filter and softener. In effect we have great water and all plumbing fixtures were saved. It was expensive (around $4,200) and does have monthly costs because of the chemicals, but to own this house it's necessary. I use pool test strips weekly to judge how things are working and that allows me to make changes as needed. I have absolutely no concerns with putting this water in my machine.
One more thing, I wouldn't listen to what a plumber says regarding when to change the filter. I never wait for the pressure to drop to change them out. Go by the look of the filter. If you wait until the pressure drops it's not doing its job and I'd say iron and other sediment is escaping.
You might want to go with a filter that has a higher micron rating and that may help with the iron somewhat, but most has to be extracted with other methods. One other method I recently found out about is air injection. Basically the retention tank has a compressor mounted on top and when water is used it pumps air into the water and this attaches to the iron and drops it to the bottom of the tank. The only issue is that it is only effective to 9-10 ppm.