Yay, a smoker!
Which one you end up with depends on how you like to do things. Do you like to fiddle with things? Would that add anything to the way you look at the finished product? Or are you more a set it and forget it? Let's say the finished product is exactly the same, even though there are those who say it isn't, would you gain any satisfaction having learned how to maintain your temps using charcoal? Me personally, I think it adds to the whole smoking experience, but seeing as how I grill several times a week, including throwing just romaine and garlic bread on the grill, gas is the way to go. I need convenience when I grill, I don't when I smoke.