Hi Demunn.
Welcome to our Mattress Forum! 
Just for clarity, I have discontinued the provision of listings of potential retailers in various geographic regions (unless they are a vetted member here of the site, because of the difficulty in maintaining such lists in a retail landscape that is constantly changing, and most importantly the confusion it was creating with the consumer members who incorrectly assumed that these businesses had indeed gone through the strict vetting and qualification process that is part of becoming an approved member of The Mattress Underground. Such an assumption is unfair to both the consumers seeking assistance, as well as the very businesses and manufacturers who have indeed qualified to be members of The Mattress Underground.
You can perform a forum search on Indianapolis or any other area and see what other businesses have been discussed in that region which may be helpful to you.
Whatever business you’re considering, I would always confirm that any retailer or manufacturer that you wish to visit is completely transparent (see this article) and also make sure that any mattress that you are considering meets the quality/value guidelines here.
I am sorry that the SOL did not work for your wife, fortunately you do know a little more about your needs and preferences. Out of the three main parts to the value of a mattress purchase which are (in order of importance)
- Suitability and how well you will sleep on a mattress,
- Durability and how long you will sleep well, and …
- Value which is a combination of #1 and #2 along with all the other parts of your personal value equation that are most important to you. (see post #13 here )
you did well based on #2 because your SOL mattress uses high quality and durable materials and there are no weak links in its design but without #1 (suitability and PPP) there is little value to a mattress purchase regardless of its durability (#2) or its value (#3) based on price or any of the other parts of value that are important to you.
Since suitability and PPP is the most important part of any mattress purchase … it is only you that can know based on your own actual sleeping experience and every method you may choose to predict this will have some level of risk involved and that the risks involved in some are higher than the risks involved in others.
The most effective way to predict whether a specific mattress will be a suitable “match” for you before a purchase is based on your own careful and objective testing. If you are not able to do testing in person than the best way is to base your choice is a more detailed conversation on the phone with a knowledgeable and experienced online manufacturer or retailer that has your best interests at heart and can help “talk you through” the options they have available and help you choose the mattress that has the best chance of success based on the information you provide them and the “averages” of other customers that are similar to you. You may wish to peruse our Trusted members here, all of which I think highly of and have a great deal of experience in helping consumers find the best match. Some of them are experts of our site as well and if you
While of course I wouldn’t be able to tell what may cause your wife’s back pain as there are entirely too many personal variables involved, including items such as your BMI, somatotype, sleeping style, levels of flexibility, core strength, sensitivities, and preexisting conditions for most people the lower back pain is associated with poor alignment due to sinking too deeply into the mattress with a construction that may not be as supportive. But of course this is a generalization and she would be the only one that can assess this with certainty through her careful testing of all the factors that may contribute to the back pain she is experiencing.
There is some information about the many different symptoms that people may experience on a mattress and some of the most common causes behind them in post #2 here that may be helpful but you are correct that the most common reason for lower back pain is a mattress that has comfort layers that are too thick/soft or a support core that is too soft
If you have any questions about specifications or certain products you discover, feel free to post back on the forum and I or any of our Expert Members here would be happy to assist you.
Phoenix