I prefer ABS for acetone wash - gives a nice, smooth result. That said, I did have good luck with my first mini printed in PLA, so I might give that a shot.
One good advantage to PLA - since it doesn't react with acetone at all, it'd be a simple matter to use ABS supports and a PLA print. I haven't had great luck with other dissolving support materials so far.
Looking over on your other thread, I see the file is no longer available, any chance you can re-upload it? Would love to see your settings.
And yes, support structures are definitely an art, one I am slowly endeavoring to master. Its even more important with DnD minis which tend to have a ton of overhead I can never seem to make look that good. But, I've got some guidance going now so will see what we can see.