I can't answer your question about demand for the fields you listed.
But I came out of a top local masters/certification program and could not get into MoCo due to lack of open spots in my specialty (secondary) the year I was applying. I went to one another school system, and was happy there. I'd suggest you research Arlington, Fairfax, DCPS, PG and Howard. Decide to which (if any) you'd be willing to apply. Due to anti-poaching policies however, it's not always easy to change school systems. Not impossible at all, just not always easy.