Yes there are, some of them are Mgs2u, AF-Hobby and Gwing

yes. well, in the hands of a skilled person, spray paints can be as nice or nicer than AB.. but under the same hands, Ab will give you a smoother finish due to the consistent spray pressure.

1. Spray paint comes in a can, so its pressure is not constant. As the can run out, so will the pressure thus it will gives you an uneven finish.
2. Spray paint is highly dependent on temperature and humidity, the hotter and drier it is the better it'll spray.
3. Spray paint is a bit wasteful since the first burst of spray is always too much so we always have to start away from the targeted parts to avoid overflowing.

If you are making a comparison, then im guessing that u are getting into painting ur kits and wanting to know its pro and cons before making a commitment on which path to take. If so i'll highly recommend ppl to invest in an air brush set cuz in the long run, its actually cheaper.