The upside to running a parallel four link is the fact that you get binding in a way that it will act like a swaybar. Fourlink is better in every other way IMO, but obviously is going to give you more articulation which isn't a plus in drag racing.
In a drag racing application, you also don't need a long trac bar/panhard. The reason they are so long on front axles is only to match the draglink so that you don't get bump steer.
Also, the longer it is, the less lateral movement the axle will have while traveling, but you shouldn't have much travel drag racing, like you would with a 14" off road suspension.
You could do parallel four link, with johnny joints (or ballistic), truss the rear axle, and run a panhard from the frame rail to the top of the truss. That way you're actually gaining stiffness and traction for the added weight. And JJ or Ballistic Joints are going to hold up to winters instead of noisy heims.
Oh, and shocks are usually worth their weight in gold, but like people said, the good ones need rebuilding yearly.