Dkzzzz, The stock Rega counterweight is 100gms. A heavier weight is necessary to counterbalance heavy MC cartridges so 130gm c'weight will not damage arm bearings. If you don't want a 130gm counterweight Groovetracer has 110gm c'weights as well.
I would also suggest buying at the very least an inexpensive tracking force gauge.
I would also suggest buying at the very least an inexpensive tracking force gauge.