Our iron reduction system would be the place to start.
http://www.waterfilters.net/Iron-Reduction-Water-Filter-System_p_0-889.html
The iron reduction system will filter water for your entire house. You would install it before the water softener. There are 3 stages to the system: the first stage is a sediment reduction stage that reduces sediment down to 5 microns, the second stage is the RFFE-20BB which reduces iron up to 3 ppm, the 3rd stage is the RFC-20BB filter which is a radial flow carbon filter which reduces oxidized iron and also will help with the sulphur smell.
It is important to reduce sediment out of your water, especially with a new house, to preserve your water softener and appliances. Otherwise, sediment can build up over time. The sediment filter filters down to 5 microns. Any sediment under 40 microns, you cannot see but it is still important to reduce out of your water. The sediment filters will need to be replaced the most often and are the cheapest. The amount of sediment in your water and your usage will determine how often the sediment filter will need to be replaced.Generally, the sediment filter needs to be replaced every 3 months.
These are the 3 filters that are in the system:
1)
http://www.waterfilters.net/culligan/wholehouse/replacement_filters/DGD-5005-20.htm
2)
http://www.waterfilters.net/Pentek/wholehouse/Specialty_Filters/RFFE20-BB.htm - There is a graph on the spec sheet that shows the life of this filter based on usage and iron level in your water:
http://www.waterfilters.net/PDF/Specialty_Filters/RFFE20-BB_Filter.pdf
3)
http://www.waterfilters.net/Pentek/wholehouse/Carbon_Filters/RFC-20BB.htm
The carbon water filters can help with sulfphur reduction but depending on the level of sulphur, you may need a larger sulphur reduction system such as this one:
http://www.waterfilters.net/Iron-Sulfur-Whole-House-Filter-W-410-ISF_p_0-493.html - This system is the size of a water softener and reduces hydrogen sulfide, manganese, and iron up to 5 ppm. These are more expensive than the filters so I would start with the filters and see if it takes care of the problem. If you do end up having to get a larger sulphur system because of very bad sulphur, you can still use the iron reduction system and put different filters inside of it. Many people use it for 2 stages of sediment reduction and a chlorine filter. This helps filter out the sediment before reaching all your appliances, shower water, etc. The system can use any filters on the following page:
http://www.waterfilters.net/culligan/wholehouse/replacement_filters/Wholehouse-20-Inch-Big-Blue.htm
Thank you,
WaterFilters.NET