[villagetinker]

I am not sure but both Lowe's and Home Depot sell these, they MAY have installers. As for piping, wiring, etc., if you are in Sumter County, you can go to the building department in the Sumter County office (Pinellas Plaza, copper topped building). They can email you the entire set of plans, this will give you an idea of what might be in the wall.
One other word of caution, I have a concrete block wall house, and have found a few areas where the wall was filled with concrete, so you may need to drill some test holes to see if you have filled block or hollow block in your specific location. Make sure any wood used is TREATED to avoid termites.
As noted above, the doggie door should never go outside, but into a screened lanai or birdcage should be acceptable, and this needs to be lockable if a person or other animal might get in.