What you have described is basically what we do (I have an 8 and 9 year old). We use Singapore have used RSO, but plan to switch to Kolbe science plans for middle school. We use AAS for spelling, just becasue it works for us but I think R&S looks good too. We are also using CAP for writing because after WWE and FLL 1-3 I didn't think they needed the MP 3rd grade writing. For 4th I think we will probably switch to CC since both MP and Kolbe use it.
We do some of it orally so that it is not so workbooky. We do the Famous Men, literature and Christian studies guides questions orally and the the kids narrate/draw on the topic (a good paragraph for each subject).
I am very happy with it. We plan to register for Kolbe starting in middle school and use it through high school. We may sub in some Memoria Press