Keep buying items from the shop with good counts for each. It may be worth your while to try to find equipment with more than one on a single weapon or armor. It can speed up the process some after combining the two before subduing them in the Item World. Max for Statistician is 900 and max for Armsmaster is 1900.
PSN: aces4839 Of course we can talk, zam, dood. - Prinny from Disgaea 2