+1 on what Maximilian says. Take note : the bigger the wheel, the closer to wedge the grind will be. Double hallows use two sizes close to the same, like 4" and 6". So it all depends on what you want to do. A platen is a must if your going to be thinning scale material shaping long straight lines. Even rounding the top of a tang.

Second thing to think about is belt grit. The cost of your grinder is nothing compared to attachments you can add :<0)