They all use the same internal parts.
I suspect that this is generally true.
Remember that the voltage is what matters. If you get one with a higher amperage rating, the device will only draw what it needs/wants and/or can use at the moment.
semi-off-topic - apparently they draw a very small current continuously whenever plugged into the wall, even if no appliance is actively draining them
"if you can feel warmth then they are actively feeding"
