I love the name, both spellings. Very handsome. But I prefer Stirling because I have a thing for Scottish history and it reminds me of Stirling Castle.
Stirling is also correct, it's a place in Scotland. I go back and forth on whether I like Stirling or Sterling better. I like Stirling better since it's not an adjective, but I like the look of Sterling more.
I also went to school with a Sterling. I think Sterling can be cool (as long as the person is "cool" enough to pull it off) but Stirling doesn't look right.