The ten gallon's not going to do much for you, really.
I'd concentrate on stocking the 55, and then you can use the ten gallon as a grow-out, if necessary, or as a quarantine tank, or even as a hospital tank.
Ten gallon tanks just get most people into trouble, because they're easy to overstock. Stocking small tanks is actually a lot harder than stocking larger ones, and small tanks are also harder to keep clean.