My votes are all for your choices of Claire Voyant, Horatio Clocksworth, Sophie Historie.
I agree with others in thinking 'Rhys' might need a better replacement... doesn't sit right with me. Last name is perfect, though. Byron was a good suggestion, I also like 'Elbert', 'Fitzwilliam' (Mr. Darcy's first name), or Quenby (means 'woman's estate', lol)
Quenby Lovelace? Elbert Lovelace? Fitzwilliam Lovelace?
I also agree with your choice of Ingrid, but Cosmos seems a little lacking in imagination-- its too obvious to be entirely funny. How about Orbit? Orbits? Orbitson? Or maybe 'Aether' (Titian god of the upper regions/the heavens)?
Ingrid Aether? Ingrid Orbitson?
Maybe I'd just leave it Ingrid Cosmos. Whatever works.... your stories are always hilarious. No need to change the name if you can't find a better.