Yeah, it's open to whatever we'd like.
The somewhat comparable infernal is CR 26, so yeah, probably upper 20s, low 30s for CR.
Shall we work on the regular SLAs now?
Common Spell-like Abilities Among Angels
aid - all but planetar
commune - monadic and movanic devas, solar
continual flame - all
cure X wounds - all devas
detect evil - all
discern lies - all
dispel magic or greater dispel magic - all but movanic deva
heal - astral deva, solar
holy smite - all
plane shift - all devas
polymorph - all
raise dead - all except astral deva and solar (solar has ressurection, though)
remove curse - all
remove disease - all
remove fear - all
"Greater Angels" (solar and planetar) Only:
earthquake
greater restoration
lesser restoration
mass charm monster
power word stun
waves of exhaustion
waves of fatigue
Always active on "greater angels": detect evil, detect snares and pits, discern lies, see invisibility, and true seeing. They can be dispelled, but the angel can reactivate them as a free action.
We've got the last bit already covered in the localized omniscience, although we should probably add detect evil and detect snares and pits to it.