Professional Title Network
Chicago Title and Trust Company
Both will insure if you borrow against a tax deed or if you sell to someone else (will insure the buyer's purchase price typically).
They will not insure your tax deed as such (if you neither sell nor refinance).
Best to use the attorney that helped you get the tax deed as they are also title insurance agents (get a commission fee) and the title company will look more favorably if an attorney had done your case.
Last time CTTCo really put us through the ringer - we took a blanket line of credit over 4 tax deed properties and they were going line by line over each party of interest and each lien on record. "Why did you not serve this or that?". Had more questions than the judge. Took us 4 weeks but we got it done. Had to sign a couple of personal undertakings for 2 of the liens even though we had court orders saying those were exitnguished/merged (one was a weed lien, the other one some old taxes that our attorney had merged through our tax deed).
Good luck and let us know which companies worked for you.