With either of these 3.1 should probably be the goal for configuration and not attempting to run older 1.3 games.
Agreed on the 3.1 roms.
And WHDLoad for the games...

I really do like my A600: ACA630/25, KS3.1, Indivision ECS, 4 GB disk-on-module, 3C589 NIC... Really nice system.
And I also like my A500: A508IDE, KS3.1, Indivision ECS, Power PC Board, 256 MB CF, 68010 cpu. Also really nice.
My much 'heavier' machines like the A1200 and A2000 are put away in boxes, I prefer the A500 and A600 for normal use. Maybe that'll change in the future, but for the time being I prefer using my 'small' Miggies.