Which version of Deadlands? The original Deadlands or Deadlands Reloaded (which uses the Savage Worlds system)? If you are using the original version of Deadlands, the difficulty I see could be with Hucksters, because they need a separate Spell Deck that's not necessarily a problem, just a difficulty, and the more Hucksters you have the more decks of cards you'll need. It's been close to 10 years since I played Original Deadlands, so I can't remember if each player needs an init deck or not. If so, you're going to have a lot of decks all over the place... I'd probably recommend using the newest version of Deadlands, which would make things a lot easier. I've been using Roll20 to play Savage Worlds for the past couple of months and have found the system actually very accomodating, so no major issues that I can think of at the moment, system-wise.