Ahmed,
I don't know whether you are searching the UK or not, but my instinctive reaction would be to check the census which covers the time you really know about when these gentlemen owned the farms. If they were resident farmers then the information provided at the time of the census should give you most of what you are looking for. If their employees lived on the farm then from my understanding, they will be named also. Sometimes, at least in England where I've tracked some of my people, the workers lived in cottages supplied by the owners, maybe they were named after the owner?
My problem is exactly the reverse. I have an ag lab and his family living in a cottage which I firmly believe is named after the owner/builder but can't find his name anywhere.
My expertise here is almost non-existent, I'm just working on what I've found in searching for my own family in England.
I am sure there are people here who know a lot more than I do, and I'll be interested to see what advice they have to offer. Who knows, it might even help me too!!!!
Best of luck in your search,
Philippa