It's all in the front end...we have problems with that rig with our 1.5" kit. The caster angles get screwed up and the thing turns into a death wobble machine=> you can't lift it any higher or your wife would put it in a ditch after she hit a speed bump at 20 mph.
All you had to do was ask the man

The Overland was even worse.. fact is, it's not an appples to apples comparrison, so don't dwell on it.
ANYTHING is doable with the right amount of time, skill and cash. I'm throwing a high pinion D44 and a GM 14T under mine next month because I did the research on steering and the frame (stole some ideas from Jedi, too, but I don't think he'll mind...we thought of the C channel frame supports before I read his post here, anyway...that dude has some skillz!) and have the tools, materials and time. If you want an IFS 5-6" kit, you can make one that works, it's just going to cost you a BUNDLE of cash to strengthen everything so you don't break stuff. The plan on my SFA is to get it in all under $2000 in parts...labor, well, you're on your own there.
I wish I could tell you us MFR's where going to pop out a great 4-5" lift for them, but it probably won't happen. We're going to have to go by way of the Tacoma guys and do it ourselves ie SFA conversions or Al's hybrid good looking set up. Working on your car isn't rocket science.. so grab a tech manual, start reading and see what you can do!
Good luck!