Sidekick Vise on an Arcflat Table

I made a welding table ages ago using import platens which use the 5/8" hole pattern on 2" centers with 4" side skirts.

I would love to mount a Sidekick vise to my setup, which looks like it might fit with minimal modification, but I also saw that there’s two options (FA75-SDV800 & FA75-SDV400). Can someone help me out with which option would be easier to modify for my table?

The holes on the Arcflat table are 1" from the edge on both the sides and top.

You would need the Dragon wagon vise. The original holes won’t match your table. Your table holes are too small and in the wrong location. You’ll have to drill holes that match the dragon wagon table or modify the vise. Some machining would be required.