I have a GFCI switch+outlet all-in-one in my bathroom. Granted it's next to the sink but it has a switch in it. I'd suspect that it's possible to wire a half-and-half to be just a switch only but it may be a code violation. And regarding a GFCI switch ONLY unit, I don't know.
Be sure you have a deep gang box because GFCI outlets / switchers are need more 'room' for wiring. Oh, IF 'others' say it's OK to use a GFCI half-and-half (outlet + switch) unit, I hope there's a 'way' to externally 'prevent' people from even TRYING to use the outlet part of the unit. (Maybe this is why it would be a code violation.) Maybe, like, you can fill the outlet 'recepticles' with grout, or something. I DON KNOW. I have to believe that you can buy a stand-alone GFCI switch-only unit.
Well, I'll TRUELY leave this Post to a Pro. I just thought I'd share what I knew. And it's good you're asking. My best to ya and hope this helps.