mazberry runs a 2 link with a panhard if I remember correctly, and tows his mazda, and enclosed trailer too. I seems to work well for him.
there is no "best" anything. suburbans are big, and there is more room than say a tahoe. the choice of which method you use to locate your axle is really up to you, your wallet, and the shop you choose to take your vehicle to.
personally i like the 4bar set up from air ride tech, all the ends are poly-euethane bushings, and all bars go straight forward. then you add either a panhard bar (if you have enough side to side clearance on your tires, since a panhard moves the axle a small amount side to side when going up or down) or you use a watts link, which has no side to side movement.
with a properly installed system, be a 2 link, 3, 4, 5 , 6 link, or whatever you use, if its strong and done correctly, you should not have any problems with towing.
yeah if i did it over or different suburban... i would use the parralle bars and panard/ watts...a buddy has a tahoe with it and it really works well! also triangleated means cutting that floor up...i still had plenty of room for my back seats, but a lot of new floor....good luck...