most of the kits use the same O.E. parts, koyo, NTN etc.
Most brand name kits Gates,Dayco, Contitech etc. all use same tensioner and rollers no advantage over the genuine subaru part, subaru dont make the parts
see example gates kit in image all O.E. bearings and tensioner, dont know what waterpump is in that kit but O.E. is Aisin