I don't particularly care for twin names to be themey but I think you could do worse than simply having them begin with the same letter. I agree with
Rachel Shaina that the names aren't particularly 'matching' otherwise.
I can't think of many twins I know myself. The few I can recall are:
Angela and
ChristinaKatie and
Sally (not sure if
Katie was a
Katherine or not)
Harrison and
Hamilton (Sister
Heather, all with mother's maiden name for a middle name. Now
that is a theme!)