From your discription of the front suspension, it sounds like you plan on turning some corners pretty hard. With that in mind, personally, the caltracks would be out. I think the way they are set up would put some real binds on the mono leaf under hard cornering, enough to scare me.

Along the same lines, I would think that by de-arching the SS springs, you are going to loose any advantage they may have over the stock HD springs, esspecially once you throw a rear sway bar into the mix. The shorter SS springs aren't going to help much in the cornering either.

I'd do the HD springs, sway bar, and some good rear shocks. Might consider adding an extra leaf to the spring packs and also adding spring clamps on each leaf end on both of the front segments. Be carefull about flattening out the rear leaf springs too much, if one drops past center and the other doesn't, it can shift the rear axle. Gene