Loaded question because we don't know the existing conditions. Provide a picture of your space and you will get better advice.

HI -- If you are just needing the sliding glass , then that would be done by a glass company. If it is to do the whole opening and counter ,.. a kitchen company or a general contractor that does commercial spaces.

A good handyman could handle the entire project with the exception of fabricating a granite counter top and the glass installation. You will need to hire a glass contractor to do the window/pass through. You may need an electrician as well.

If you are in Florida, you need a licensed contractor and a permit.