I would recommend contacting an independent engineer for an inspection, then taking that report and scope and get bids from several foundation companies. It will cost you a little more up front, but likely save you more in the long run vs. having the foundation company come and prepare the scope. They are more likely to recommend more repairs than needed than the engineer.
I recently had Crosstown Engineering do an inspection on my own P&B home ( was about $575) then sent the report to several companies, Stratum Foundation was the cheapest quote. Some other companies you might want to bid: Integrity, James Bond, Brown Foundation, Integrated, Arch, Structured. The last 3 are typically considered best in class and as such will likely be more expensive.