[ano]

You will have many ArchTheurgs with S4. Add a skullcap and get S5 for Angelic Host. As for Heavenly Choir, it requires S7F2. If you are lucky enough (as Jazzepi counted in a neighbor thread about MA Man, the probability is about 1,25%) to get an ArchTheurg with S4F1, then use ring of wizardry, skullcap and crystal coin (you will probably have access to all by that time). If not, add some unique astral booster like dimensional rod. You may also aim to cast Wish instead of Heavenly Choir using a S5 ArchTheurg.