The old green Powermatic drill presses (I don’t know, that looks like the plural of press to me) seemed to fall into to categories: Open belt antique-style press, or massive, variable speed units that could drill a 12” hole through a slab of solid granite! The new Powermatic models all have nice, large tables, enclosed belts, and an a few cases the old variable speed.
My advice is to buy the biggest press you can afford. I know, there’s nothing exciting about a drill press, but there’s also nothing more frustrating than having your project hit the column with the drill bit 1/4” shy of your mark! Remember that a drill press with an 18” swing will drill to the center of an 18” circle, meaning that you can only squeeze a work piece 9” beyond the bit. Tricky eh?