Yeah, at the end I too only needed the few things you mentioned (stiffer diff, damper set with blue and red springs, better servo saver) along with a solid servo mount and the 1 degree toe-in rear uprights on my M03. My M03's rear tended to slip out often during off-throttle turn-in, so the rear uprights greatly stabilized that.

Other then that I have the extra weights up front in the bumper and the front stabilizer. Thing drives VERY well. Oh and bearings. My near bonestock M05 needed even less parts to get it going nicely (just the stiffer MR diff, and dampers/springs only, no bearings either); will try the zip tie over factory servo saver later today.