Surge and outlet amps are not the same thing. You get one (surge guard) to match whatever power connection your RV is, and it should still protect you no matter what outlet you plug into.
The best thing is an EMS (Electrical Management System) that not only has surge protection, but other functions. It will not allow miswired pedestals to damage your RV, as well as cut power to your RV should voltage get too low or too high, and protect appliances from these conditions too.
The EMS are higher than just a dedicated surge guard, but save money in the long run, should their protection be needed. They make a hardwired and portable version.
The Progressive Industries seem to be the favorite of many members here.
More reading here:
Progressive Industries RV Surge and Electrical Protection industry lea