Thanks, your suburban is one of my favorites on here. As for radius arm vs three link I personally feel that the extra complexity and design time required for a three link is not totally worth it for a DD/wheeler truck. Radius arms are so simple it is pretty hard to screw them up and I can turn it into a quasi three link by unbolting the passenger side upper link like so....
With my springs full soft and the upper link disconnected I can get the front tire three feet off the ground before the back tire lifts. That is pretty good considering the back is still worn out old factory F250 springs and no where close to using all the available shocks back there. The other issue with a three link is that you will probably need a sway bar to cut down on the body roll, a radius arm setup naturally acts as one so it will help but is not as important. My truck will crawl over just about anything and I love how it works so I vote radius arms!