Will a rooftop antenna work with a digital converter box?

Short answer: Yes!

Longer answer: Digital TV and Analog TV share much in common; they are both radio signals, and in the same bands -- in fact the channel number assignments for the physical channels are identical. Your rooftop antenna picks up the radio signal no matter what is encoded on it. It is up to the receiver (your converter box, f'r'instance) to make sense of what comes from that antenna. Select a VHF/UHF type.