If your're good at stone cleaning / restoration / hard surface repairs, matching etc and you have the time (money to live) to build up your business that's the way I would go as it's more specialist therefore better margin / gross profit and you will soon (3 years) build up a customer base who know you "do what it says on the can" and solve problems for them.
Yes you could make more immediate money carpet cleaning but so are lots of other people trying to do that at the moment because of the times we live in.
Why not do both? ..... with the idea one is putting the bacon* (it might be streaky or miss-shapes!) on the table while you plant and grow your seeds for the real, more specialist business.
Best of luck, I'm interested so let me know how you get on.
Phil D
* For some reason you sound American? If you are married to a Brit ask her about 'cans' and 'bacon' :-)