which r-pod should I buy?

Okay a little electrical theory. Power ( which is measured in watts) is Current (amps) times Voltage.

The formula is written like this P=IxE. So if you turn the equation around then I (current)= E (voltage)/P(watts).

when you plug into the post at a campground the campground provides you with 120 Volts at 30 amps. This goes into a distribution panel in your Pod. This is like your breaker panel in your house. At the distribution panel the electricity goes through breakers to different circuits  in the trailer. The plugs are on a 15 amp breaker so you can run anything that uses less than 15 amps on that circuit. So to calculate how many amps an appliance uses. you take the watts, in this case 1800 for you hair drier and divide it by the Voltage. so 1800/120=15 amps. So if you have nothing else plugged in you can use your hair drier.  If you do overload the circuit then all that happens, as has already been said, is you trip a breaker that has to be reset.