Welcome from across one of your other borders! I have heard good things about some public school districts in Md. - Montgomery county stands out in my recollection.
We did testing via our school district because ds was not not happy and I couldn't see the point of waiting until 3rd grade to find out if his possibly being gt was the reason for the bad fit...it has helped a lot, but we have more thorough testing in our/his future, too. Possibly with JHU-CTY, but more likely someone in Va.
Fortunately our school has a program and so far it's been very good, but that's only a few months of history. I like Dottie's suggestion of working with what you've got at least initially to see how far it can go. Good luck!
Masterofnone, I would be very curious to find out your impressions of the testing process via JHU; they are somewhat near us and I just found (via Hoagies) that they have a gt and ld assessment facility. I thought they just did the SCAT testing/talent search work.