I would check the gifted school carefully to make sure he would really be "accepted" with his various issues. Some gifted programs seem more interested in the perfect high-achievers than than kids who may actually have very high cognitive ability but various quirks or disabilities. You can apply based on scores but once he is there you cannot hide things and you don't want a negative attitude from the staff. KWIM?
Our local "school within a school" gifted program happily took DD and told me it was not a problem that she was 2e but then once she was there it became clear that they didn't really know what to do about her issues. It wasn't that they were deliberately trying to make things difficult, but they were not going to go out of their way to accommodate her various quirks, either, or do any interventions so that she could make real progress.
You also want to check the gifted program in the regular school and see what the work or environment would actually entail. Sometimes it sounds great on paper (or on a website) but it's actually pretty meaningless in terms of what the children are given, or the amount of advanced instruction or time spent on advanced instruction or work.
