SR games seem to do okay here. I'm in one, in the process of hopefully joining another. As far as Roll20 handling it, so far the game I'm in uses Chummer to handle the character sheet end of things and we roll the dice manually in Roll20. So, if your dicepool is 8, then /roll 8d6>5 will roll and give you the number of successes. I'm not sure how well or if the built-in character sheet works.