Oh Sue, you have such a good heart - how blessed your dc are that you are in such thought about what will be best for each of them!

It is just too dangerous for you to be looking at other HOD guides right now because they are all so full of goodies, and you are just going to be goodied out!

I think doing LHTH, LHFHG, BHFHG, and PHFHG first shot out of the barrel would be too much to start with at once.

Your 9 yo is going to do just fine with PHFHG. My ds was 8 when he did PHFHG, and writing was not his thing. He did very well with the gentle guiding of written narrations in the plans. He also bloomed with PHFHG's creative writing lesson modeled after RLS's poetry. Every child can be successful writing with the lovely creative writing lessons planned in PHFHG, and no matter whether a child is not a writer or is a writer, they will help each child grow. Juliekay and Lynnh gave some practical advice to keep in mind as well. Sometimes a few months of growth does wonders! HTH!
In Christ,
Julie