As mentioned above, "racing" and "street" driving should be looked at as two totally different entities. You either build your car for one or the other. Want a street/strip car? Then you'll have to make sacrifices. Sounds like your Duster will be a racecar mainly. For that, the Cal Tracs work awesome. I think there is some room for improvement over the Cal-Trac design, but they have the reputation and name that everyone knows. There products definitely do work.
Id like to design something with a little more adjustability in it, but it may be a little while before I can get to it. Think of the Cal-Trac as a "simple" ladder bar. Thats the point of them...it takes the rotational movement of the rear axle and applies it under the spring eye, which in turn, helps to lift the car. Same concept as a ladder bar, but you dont have to worry about coilovers and all that.
