you may as well get both - most are sold together and the difference in price isnt worth not having the converter. it will also help regulate the power flow, which, depending on where you go, can be a little spotty.
I just got back from being in Europe. The converter saved my camera from being blown, as it took the hit from a power surge that wiped a number of devices in the hotel we were in.
Get the converter, comes with the adapters. Cheaper than a replacement iPad.