Sorry to take so long to get back to you, the holidays sort of cut into my reading/research time. :-) Alan Pitts' note seems to be right on the mark, I have not been able to find any records of the members of the militia companies, nor have I found records of the Mexican War (two companies from Lauderdale County) even though I expect that unlike the militia records, these actually do exist.
I did find both of the names you mentioned in the census data but I expect you already have this information.
I did find the names of half a dozen or so militia members in the book "Lauderdale, Mississippi's Empire County: Volume I: The Early Years, 1830-1865" by Fred W. Edmiston and thought I might come across the individuals you are interested in. Unfortunately, I did not. I have passed through the counties early history and am begining the final chapters on the Civil War. I guess it's unlikely that I'll run into them now.
Other than James Durr who I mentioned previously, the only other Durr I found was Frank. Frank was a former slave who had some quite interesting things to say about Lauderdale County in the American Slave Narrative Project.
Sorry I couldn't be of more help. I'll keep the names on my list in case anything turns up in the future.