According to Everton's Handy Book for Genealogists, Kinney Co, TX County Clerk has birth and dth records from 1903, marriage rec from 1872, div, probate, civil court, and land records from 1873.
I don't know how far away you live from Bracketville, but if it is any distance, you might want to check out what the Family History Libraryhas microfilmed first.Use the FHL catalog online.Any of the films can be ordered out to your local Family History Center.Then if you make a trip, you will have already covered some of your research and will have more time to look at what has not been filmed.
I did a quick look and FHL for Kinney Co, TX has Land 1873-1977; crt rec minutes for Dist and County courts; probate 1874-1931 and marriage beginning in 1872.
You probably know this, but if you do not find land sale about time of death of your ancestor, keep looking.You do not have to record sale of land, and often it is not recorded until a sale is made outside of the family.
In index if a family name shows up with "et al", you sure want to look at that one.Et al means "and others."Index only shows first name on the document and not all of those other people listed who probably also are family members.That first name may be the name of a son-in-law, that often throughs researchers.
If you've never been to Bracketville, and like the old west, you might want to allow some time to visit the old movie set there.It has the remains of the Alamo built for the John Wayne movie "The Alamo", and lots of old westernbuildings etc.It's been a few years since I was there, but I thought it was one of the most realistic looking sets I've seen.It's still being used for movies and TV.