as a specialist (i think that's what Ed. S is, correct me if i'm wrong) you are not able to do private practice work in new york. you also can not teach as an adjunct (or assistant or any type of) professor, and getting a job with a school district is much harder (since you are competing with candidates who have a PhD). the doctoral programs allow you, if you want, to take the licensing exam to become a licensed psychologist and do some of the same types of things someone coming from a "clinical psychology" program would do but with your own awesome specialty of being school-children oriented (assessment, consultation, intervention!)
unless you live in an area where PhDs are very rare and/or your state allows you to do more than just work with a school district, I would recommend the PhD. Not only will your training be better (you'll be better at your job!) but doors will open. going from a specialty/masters program into a PhD program should not be difficult if you decide to do so in the future.
as for my career goals, I don't know right now.