Start with PG setting–and on maple. And a scrap piece first.
If you’re going to paint after etching, are you planning to apply only one color? Given it’s size, can’t imagine you’d have room for more than one color… So best to change the image to grey scale, then decrease to 2 colors to make it black and white, so you only have etched areas and unetched, since painting over it will make trying to do gradients worthless–and for so small, doubt they would even show up. I really don’t think at 2" wide you’ll get the fine details to show up… so test on scrap first to figure out what works best for your material.