sev sev, signature sound both have custom air ride kits in their protege5s. I also know of a sedan that had a setup and is upgrading to a newer setup. You can see SevSevs setup in his videos on youtube.
If you just want low and no handling go with sleeves. If you want to be able to drive that car and have it handle like its on rails save the money and just buy coil overs, that way you can setup the car properly at the height you want.
i would just look into a bag on strut air system if you want to be able to change ride height often and still have good handling. I have coils and i set them up once and left it there(took me about 2 weeks) as it was a pain to make sure i had them even and at the height i wanted at all 4 wheels