Hi Kathleen I don't know where you are based and if you have any cat rescue groups nearby but they may be able to lend you a kitten trap and/or give you some assistance. Kitten traps are not automatic and so are not so clanky and scary although, to be fair, all trapping is stressful. A large towel or blanket to cover the trap calms the cat - a bit like covering a parrot cage to silence the bird
Personally, I would strongly suggest you have Hobbes neutered asap. In my experience, it calms hormones down and, while all cats are different, many semi-ferals tame down brilliantly with their fosterer/owner in due course. The younger the better though. Keeping Hobbes indoors for a few weeks or longer would be a good option - you don't have to take time off work but confine him to one room with litter tray etc and radio on so he gets used to voices. Lots of toys on rods/wands are good to interact with scaredy cats - saves your fingers!
As others have said, Calvin, who seems tamer, can be vaccinated as she seems ok to be handled. (Initial vaccinations are in 2 stages, 3-4 weeks apart.) Bearing this in mind, if Hobbes is not going to be easily picked up again, probably no point in doing an initial vaccination at the time of neutering if he won't make the second stage... Best to wait until he is tamer.
Feliway plug in is a great idea. There is also a Feliway travel spray which is good to spray in cat carriers. I'd wait on the Felifriend spray for now - it's brilliant but it doesn't sound like Hobbes is ready to be handled so perhaps it's a bit superfluous for the time being.
Sounds like this pair have landed on their feet. Pics pls!!