Jig looks cool.
Can't really help on the bearings, only bearings I've ever replaces were in a well used 2nd hand 72 and I used Saito bearings. They all depend on blowback to lube the cam gear and I would be a little concerned the non sealed bearing would let too much by the bearing and not enough up to the valve train. In reality it may not make any difference, I really don't know.