I have 5 year old son as well and it looks like we will hs next year. It took me a few months to get used to the idea, so I am no longer freaking out (most of the times :))
Join a local hs group and see what they offer, when they get together and such. It helped me a lot.
You said that you are looking into Waldorf schools, as far as I know they are not too gt friendly. For example according to their philosophy kids are not ready to learn to read before they loose their baby teeth. Well, that sure wouldn't go well with most of the gt kids. Look very carefully at their curriculum and where they would place your child before you go this way.
