I would pick Poplar, soft Maple, Southern Yellow Pine, mostly depending on price. Not the dead low end of Janka, but all under 900. So none are hard. All are easy to work, and will be plenty stable for woodworking uses. All will take paint well too.
If the piece is well supported, and doesn't have large overhang ledges, don't rule out MDF, though the edges will need some form of Fascap tape or similar, as they are like a sponge, and getting great pain on them isn't easy, unless you totally cover them. This same thought can also be applied to Plywood, though with plywood I would definitely suggest a good primer like Kilz to stop the telegraphing of wood grain, through the paint. Using Kilz even on hardwoods, or soft with a paint finish is always a first step for me anyhow, same reasoning, it stops the telegraphing of grain lines through the paint.