If you plan on keeping the original bolts for the links, they're different diameters (M12) for the inner front set. I used a 14mm (.551") drill to bore the spacers for all positions and will not be putting the M12 bolts back in. I also raised my pickup points by 1.5" so I was making new holes anyway.
0.584" will allow the bolts to pass through easily and be within acceptable tolerance for slop. On the bushing though, I'd use as close to bolt diameter as possible to eliminate slop where it counts.
FWIW, I'm using 1x12" alu center sections and 3/4 shank and hole ends, bushed down to 14mm. It may be overkill....but I don't want them breaking. If they're good enough for 700+ HP outlaw sprintcars, I think my little project will be okay.