Window ledges are great for starting seedlings when its good weather, but its pretty unrealistic to expect to keep it outside once it starts getting larger. Most people usually just move them inside once they lose their trainer leaves.
And for the light that you get, I think you'd end up with a small, stunted plant, due to not enough light, I've had several plants die on me when they were growing due to not enough light.
That being said, it'd be worth a shot, get one seedling out on the ledge and have the rest inside under a light. See how the one outside goes, if it goes well, bring the rest outside, if not, bring the one on the ledge in.
As for clones taking root in sunlight, it should be fine, as long as you have enough sunlight.