Why not Vassal? The Vassal mod is pretty sweet. A bit quirky, but very pretty and very functional. The card decks are different. I'm in two PBEM games with vassal and both are going smoothly, albeit a bit slowly at times. And the surprise cards are a pain to deal with, as you will often have some backtracking to do.
I agree that Vassal is good, but only if you use the beta of the new version. Getting the older versions to run properly is often a bear, and they had serious performance issues.