You can run them all at 5V from the board to avoid using an external power source.
I'll go ahead and order a Mega in case I need additional functionality. I have a universal adapter (converts 120v to 6v/300ma) but not sure if that is what I would need as the external power source. I dont want to use batteries. I will try it out and will get back with any questions if I run into issues. Thanks again.