My answers
A mono leaf set up will also get you pretty low and back up past stock height. That said, the 4 link is the best way to go, adjustability and also how low, it will go a lil lower. The bag placement plays a big part in this as well though. Pete and Jakes, Air Ride Tech both have nice 4 links The air ride tech 4 link comes either with bags or no bags. IF you go no bags, u can use a behind axle or on top of the axle. If you go with bags, with say the Air Ride Tech 4 link they are mounted behind the axle slightly differently with sleeve style bags.
Don't worry about ride height, max height, how low, a 4 link will give you pretty well all of this.