I:IFrom what I've been told, stock type dics's with the extra plate works best. I think stronger spring do the most.
yes heavier springs help, but its not everything, the stock discs are garbage and once you go above a pipe, they will start to slip
the disc material is key too, barnett makes some decent discs, but there is a guy on ebay that sells a kit, i forgot his name but it is a very great setup
i used his discs for an entire race season on my old bike and when i pulled it apart for a rebuild, they were the only thing that did not need replacing