You kind of left out all of the important details. Like exactly what is the problem? And what kind of solution are you looking for? Given that you are in Texas, I am going to guess that you have expansive clay soil, and you are experiencing issues with differential settlement of your slab, leading to cracking of the foundation, out of level doors, possibly cracks in your plaster walls. But of course you did not say any of that, so possibly I should try out for the Mentalist TV show, or else I am so far off I should be on "It's Worth What?".
You had six foundation companies come out and offer opinions. Here is an alternative strategy for designing a fix. You hire a structural engineer familiar with foundation issues in your region. You pay the engineer a reasonable fee, perhaps $500 or $1000, they do an in depth analysis of your specific foundation problem, and recommend a specific solution that they believe is cost effective. Your type of problem absolutely requires a hands on investigation, including perhaps a soil boring, to identify the exact problem, and come up with the optimal solution. Here on the internet chat forum zone, we can speculate all day, especially since you have not given us any pertinent facts, but at the end of the day we cannot help you, except to point you in the direction of hiring a local professional who can do the inspection, and offer an unbiased opinion on a reasonable fix.