Thanks BSM and polarbear -
I've looked at all the public and private schools that might be a fit and well, the public HG school is the only one where I really felt he should go- and I really tried to talk myself out of it, because it's pretty much putting all my eggs in one basket. And if he doesn't test HG in the district test, there will not be anything, public or private that is a close second (BSM the district doesn't accept outside testing, although I'm sure our outside test aided in their being willing to retest).
I have submitted him to a bunch of lottery public schools (private schools here have maybe a couple of openings between 5th and 6th because they change to middle school in 7th) and if nothing works I will keep looking at privates.