You could always just veg a bit longer than usual, take the tops for your clones then throw them into flower after that, and by the time the clones take and you get them vegging you'll be a couple of weeks into flower on your original grow.
You cold get to where you stagger them, and since space is an issue, maybe end up harvesting two plants every two weeks or so. Which would put each pair at around 8-9 weeks of flower, and 8-9 weeks of clone/veg growth. Chop two, switch two to flower, clone two from 6 week+ ones in veg, switch two clones to veg lights and it just keeps going.
You would be vegging the clones a bit longer than usual so you can repeat the same process again, and it would give the ones you're cloning from around two weeks or so to recover before switching them to flower. Then you could get a perpetual grow going without having to make space for permanent mothers, or order tons of seeds.
Flowering clones supposedly work quite well also, that's another option since you take them at around 21 days into flower I think, so you'd be about perfect on your rooting/veg time once your flowering plants finish.
You could make yourself a cloning chamber out of a storage tote with a small T5 fixture that would fit on the underside of the lid, I own one that is 23" long and it cost like $10 without bulbs. That would be stealth since it could be opaque and look normal in a closet or basement or wherever, and you could wire in a low CFM axial fan and filter if you need a bit of ventilation as well