There are timer feeders that come with ice packs to keep the food from spoiling. I still have the one I used for Pookie, though I used it for when I thought I'd be home late and I never used the ice packs.
That said, I wouldn't leave a cat or any other animal for 2 days without someone at least checking in on them to make sure they were ok. And for cats, to also clean the litter box.
I don't understand why a sitter isn't an option. There's got to be a neighbor or someone who could do it. But then again, maybe these are the kind of people who think they're "just cats" so it's perfectly ok to leave them for 2 days straight. If they do that, I hope for the cats' sake they don't regret it.