The Oliver is just one made in China with a Oliver tag glued on. I have no idea about quality and features. I would not be surprised if Grizzly does not sell the same one at lower prices including reasonable shipping.
Only harry home shop here but I think a sliding table would be very nice. A tilting spindle seems nice but adds more to adjust and fall out of alinement.
Very seriously look at used. Not much to go wrong on a shaper unless you need cnc control on spindle height.
Bill D.