Well, I also have the Man-A-Fre 4" Safari lift and I know a lot of folks on this forum poo-poo them. They seemed to be working well for me. I have run them on my trail pig/occasional driver pig for over five years and they have not seemed to sag. They seem to flex well enough also. I don't wheel with them as much as others perhaps, but this rig gets loaded up with a bunch of stuff often-yard and construction debris, camping gear, lots of folks and dogs, etc. The ride is a bit firm still when driving around town unloaded, but as soon as I drive with a slight load or rally offroad it puts a big 'ol grin on my face. Price was reasonable and not too complicated since it was a complete kit. I purchased the OME springs with mine and I think they help also.
Anyway, I have also thought about the SO option for the future but haven't quite crossed over to the 'Dark Side' yet...All that being said, Alcans sound like the best way to go for a custom SUA lift and I have been looking at that option for my other pig-I think I want to go smaller than 4" so I am looking at options also. Oh, and I am by no means an expert at any of this.