There are plenty around... I'll list you a few of the bigger ones.
Flight-Safety: Nice school good facilites, exellent training program. Quoted price close to reality. Fairly expensive. Nice and clean equipment.
Located in Florida
Sierra Academy: Located in San Fransisco area. Expensive accomodations. Good enviroment for learning ( busy ) Facilities old and well worn. Expensive, quoted price not even close to reality lot's of hidden charges. Fairly decent training program.
Shabby old airplanes especially the multi's are worn out mostly broken.
Comair. Again in Florida, close to Orlando I have heard good and bad things. Seems to be a little bit more inexpensive than either of the above.
Once working as a flight instructor you had a Comair crew ID that allowed you to jumpseat on comair route network.
I would buy a Flying magazine and look into the classified section , there are plenty of schools advertising there.
JJ