My "babies" were older (8 months to 16 months), but I would have up to 4 sleeping in the same, small room together in playpens. It did take a bit, but they all learned to sleep through any crying that might happen before, during or after naptime. I did both morning and afternoon naps like this. Now they can each sleep through anything
. So it can work, but it does take patience ...
As for equipment, I have one high chair for each little one, and boosters for the ones that need them. I got the Ikea high chairs (they're cheap and easy to clean). And, they're easy to move around with a child in them, which comes in very handy when you're spoon-feeding 3 babies at the same time. I don't use saucers or swings, mostly because of space limitations. If I had the space though, I'd likely have 2 or 3 saucers. My preference is to have enough of each thing for the kids who need them, because it just makes life easier.
And the babies that fuss while you're making lunch or whatever -- I either let them fuss or sit them in a high chair with cheerios or toys (if they're old enough). If they're not old enough for that, I'd sit them in a saucer or bouncy seat where they can see me, and just go ahead and do what I need to do. They'll get used to the schedule eventually, and they'll learn when you're available and when you're not.