Just my .29 cents worth, but the TT-50 truing jig is essential!! I clogged up my wheel to the point it wouldn't sharpen wax! SVD-185 it the gouge jig so it needs to come home with you. SVS-50 is the skew jig and lots of folks use skews, so it will need a place in the drawer. I use the Grizzly knockoff of the Tormek, it uses the same jigs.