Low wing can be very stable and slow fling. Wing position is just one of several variables that effect stability. A little extra dihedral will make a low wing plane as stable as a high winger.
Stalling is more down to wing loading and wing shape (and some other things) than it is about high or low position. There is no reason in principal why a low winger should have a nasty stall or need to fly fast.
Just to illustrate the point, heres a model with low wing and swept back wings, that flies pretty darn slowly, and doesnt seem to have any stability or stall issues:
I think what leads people to make these assumptions about low wing models is that most low wing models are of WW2 warbirds like Spitfires and Mustangs and the like. They of course are fast flying and can be quite tricky (just like the full size versions were).. But the reason they fly that way isn't really their wing position, it's a lot of factors, wing loading and wing shape being two big ones.