Softening:

With four people in the house, assuming iron removal is in place UPSTREAM from the softener, I would go with a 1.5 cubic ft softener (vendors may refer to this as a 48K grain softener).

The following requirements are for an industry standard softener. If you are looking for a non-electronic softener, Kinetico offers the more reliable options at a premium price (and you would need to deal with a local Kinetico rep). Any decent softener vendor should be able to provide the following:

1. High quality American or German made resin. This will provide a tight size distribution for optimal flow within the resin, longer resin life, and more reliable, predicable water softening.
2. Since you have WELL WATER: 8% crosslinked resin.
3. Top basket. This serves two purposes. It sets up a proper water distribution during normal operation and prevents resin loss during backwash.
4. Gravel underbed. The gravel underbed is there to set up proper flow patterns, improve backwash, keep the bottom basket in place, prevent basket failure, and prevent channeling. Many softener sales companies like to leave this out or sell softeners with a vortex system instead. Vortex systems weigh less than gravel so they cost less to ship. In addition, they are a more expensive item that adds profit for the softener salesperson, but provides no additional benefit to the homeowner . It simply adds another piece of equipment that can break.
5. Fleck or Clack valves. These set the industry standard. Be aware that you may not be able to purchase Clack valves online. This is not a problem if you purchase locally.
6. The valve should regen based on water usage, not time.
7. Install the softener with a three-valve bypass. This will make it much easier if you ever need to remove the softener for repairs or wish to take it with you when you move. Use full-port, quarter-turn valves.
8. Noryl bypass. Most softeners are available with either Noryl or stainless bypass valves. Both are good valves, but the noryl tends to be more reliable when not used for long periods of time. This is a redundancy if you install with a proper three-valve bypass. I prefer a bit of redundancy but it is your call. If you decide you only want one bypass, skip this one.
9. Brine tank: Although either round or square will work, round brine tanks are more structurally sound and will not deform like a square tank will. Additionally, when you need a softener 1.5 cuft or larger, a square tank will most likely be too small.
10. If you live in a cold climate, ensure equipment is stored in a climate-controlled environment. This include the place from which you purchase. Frozen softener resin is damaged softener resin.
11. Purchase a Hach 5-B test kit. You will want to periodically check to ensure your softener is working correctly and this kit is your best option.
12. Since you have iron in your water, purchase an iron test kit, such as the Hach IR-18A or IR-18C.

@aliceinwonderland_id thank you for the information. I did have the water tested for Manganese but accidentally omitted it from my post. It is at 0.135 mg/L. You're right when you said I meant flow rate but said pressure. I have done a lot of reading the past week on water treatment and I'm a little overwhelmed. Thank you for clearing that up.

Since I don't want to rely on just a water softener to act as the Iron/Sulfur removal, is it your opinion that a dedicated Iron removal system upstream of a softener would be the best combination of equipment for dealing with my particular water chemistry?

Yes, absolutely, your best course of action (really the only one if you want to get rid of the sulfur) is to use dedicated iron/manganese/sulfur removal, followed by a softener. I should have been more clear.

One more thing to consider: While there is no health risk from soft water (unless you have a severe heart condition), some people object to the taste. For home brewing, it will alter the flavor of the beer somewhat. This is entirely subjective and you will ultimately be the judge. If you find the flavor of the soft water is not to your liking, you may wish to consider an RO unit for drinking water/beer brewing. I would wait until the other treatment is in place an operational before making this decision.

Great! Thank you so much @aliceinwonderland_id for sharing your knowledge. I just finished calculating my flow rate and came up with 11.76 gpm. That was taken from a just after the pressure tank. Have you come across a softener system/salt that effects water taste less than others?

Nope. They all remove calcium/magnesium and replace it with sodium - that is what changes the water taste.

You may find that you like the taste of your water after iron removal and plumb that water to a drinking water faucet and run the softened water everywhere else.

So this is where I'm at regarding Iron/Manganese Removal:

I was originally thinking Terminox. budgetwater suggested 8x44 - 0.75 cuft system based on my flow rate. Using their method we came up with 6.7 gpm, not the 11.7 gpm I got using Alice's method, I'm thinking budgets method might actually be the well makeup rate not the service flow rate though.

Now I'm considering a Katalox Light 10x54 - 1.5 cuft system, but haven't contacted any vendors yet regarding sizing. The primary reason for not going with Terminox is budgetwater stopped replying to my emails. I guess I was asking too many questions like " what model valve it has, and what it's service and backwash flow rates are".

Does anyone have any experience with Katalox Light? I understand it's a newer media. There's a lot of technical information here about it. I've read in several places that it can raise PH significantly at first, causing a slippery feeling. Can anyone confirm this? Anyone out there have this system? Any recommended vendors selling this system? Thanks!