Why on earth could you not put your two cats into a cattery? How do you think all the hundreds of thousands of cats that go into catteries manage? They are safer, well fed and looked after - people don't run catteries so they can be cruel to cats.
If you leave someone at home with them they do not know
they could get out and not come back, the could refuse to eat and if they were ill would the house sitters know what to do? I have seen it from both sides as a kennel/cattery manager and a pet sitter, and the cats I looked after at home gave me more grief than all the dogs put together -
while the cats in the cattery were far less trouble than the dogs in the kennels.