OK, thanks all, sorry for confusing things by not describing the devices - I thought I had simplified it
I can't find a 5v 3A adaptor that has adaptable plugs so might stick with one 5v 1A to power all bar the 5v 3A media player which I'll continue using it's own power supply for. Jaycar has a convenient 5v 1A with USB output which make sense for all devices except the one 3A device which I was hoping to just bundle in the same bucket so to speak.
Roger.