Hi there and welcome to the forum. It sounds like you've given this a fair bit of thought.
Have Calvin and Hobbs given you any indication that they are suffering with you being gone for 11 hours a day? Any behavioural issues? Aggressive tendencies? Odd behaviour when you're home?
If not, you could be worrying over nothing. They have each other for company and will be sleeping for at least some part of the time you are at work.
So long as you have plenty of things to stimulate them while you're gone they should, in theory, be fine. I'd be more worried if there was only one left at home for that long.
All of your solutions seem great - do all of them
Also, if you don't already have them, make sure you have at least a couple of tall cat trees for them to play on.
I just bought a cat wheel for Bryan last month (took me a while to cave and buy one because they're quite expensive in Australia - $425 with shipping). Only took him 3 days to start using it without needing to be "treated". He loves it and now uses it every day. It's somewhat amusing on occasions though as he will sit on it and cry until I go and watch him use it - like a child saying "look at what I can do Mum". He does use it without us watching though as I hear him on it when I'm elsewhere in the house.
Another option if you're really worried could be to get a friend, family member or cat sitter to pop in and play with them during their "active" times - if you know when that is.
I'm assuming you have an automatic cat feeder or free feed them dry food during this time too?
If you are truly in love with them and they don't seem to be suffering, I don't see any reason to re-home them.