It has been about three years since I put a transcription of the 1797 horse tax for the Pairh of Urr in Kirkcudbright on a website. Today I have discovered that the horse tax lists for the entire country have been digitized and is now online. There is no searchable index. The images of the lists can be downloaded or saved. The lists are organized by county and then by parish. The name of the man who had the horses is recorded as well as how many horses he had and how much tax was paid. It also records the name of the land or estate that he occupied. Typically parish registers do not record the estate a family lived on. The horse tax is one source of many that one would put on his or her list to look at while at the National Archives. Also on this website is a record of all land owners in Scotland in 1872. I look forward to more records being put online. The guide for these little known or used records is the book, Tracing Your Scottish Ancestors.
At ScotlandPeoples website the probate indexes are available to 1900. They just put Catholic records on their website. The price to access these records is very reasonable and sometimes free. The record that I think would be of most value will be the militia lists created prior to and during the Napoleonic Wars (1800 to 1815). Kirkcudbrightshire has milita records that cover most parishes in the county. I have put the parish of Urr militia records online