Can't see you pic, but it all depends on your budget and what you will be using it for, mainly street or off road.
I have a 99 Tahoe (OBS- old body style) and I installed a 3" body lift, easy to do, only cost $150. Since I do little offroading, it is the route I went with. I am running 285/75/16's which are 32.5", I could almost fit a 35 under it.
If you want a 4" lift, you could do a 2" body lift, then get the Ford keys for 2" crank up front and use add a leaves or 2" blocks for the back. If you had plans for some offroading, I would recommend biting the bullet and spending the big $$$$ and have a true 4" suspension lift installed. I did the add a leaf and Ford keys on my buddy's 2002 Chevy, looked nice, but it stiffened up the ride...he liked it. Too bad you weren't closer, I have a brand new inthe box set of add a leafs that would fit our truck, he was sent two sets for some reason.
I frequent
http://www.fullsizechevy.com there is tons of info on what you want to do on there. Or google " GM trucks forums" and there will be a few that pop up.
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'99 Tahoe, 3" BL, 285/75/16's , MT II's.
'05 Liberty Sport, -wifey's
'98 Poncho Fireturd, 3.8L, .....the purple pig!