Road Brifters with MTB Derailleurs
I don't see any problem with doing this on your bike if you use Shimano drifters. Generically there are two areas you'll need to consider:


The actuation ratio of the shifters, and
The brake pull.


Shimano 9-speed road and mountain derailers use the same actuation ratio. You should be OK here.

You don't mention which Surly touring frame you have so I can't be specific, but if its a Long Haul Trucker or Disc Trucker, your odds are good that the brakes will be compatible as well. With cantilevers you'll be OK as road and mountain versions use the same pull. V brakes will be a problem, they are not common on road bikes and the pull is different. I don't think know of a set of brifters for V-brakes. Similarly with discs, make sure that you are have, or are willing to switch, to road discs.