Welcome KatieMama! Just time for a quick note...I hope that you find a lot of good advice/ideas on this forum. It's been a wonderful place for me. I agree with knute that you are sooooo lucky to have such a supportive school environment! It is rare that a school recognizes such giftedness, and even rarer that they know what to do when they see it.
We would have been in your shoes (with a twice-skipped kid) if we had stayed in our local schools, but we transfered to an accelerated program for HG kids mid-year 2nd, after DS skipped 1st, so we avoided a second skip. The one thing we noticed about the local school was that the pace of curriculum was still too slow. You may have noticed that as well, or maybe you are lucky with your accommodating school. Hopefully your DS will be placed with others learning near his level, and that will make things better.
Good luck!