Alright, I'll share my opinion about Skype. Of course, it has its pros and cons. Pros are that it is user-friendly, it's easy to install and it is a cross-platform software which you can use on your phone, tablet, pc, etc. You just login, and bam, you're in the chat. It's also good because you can very easily join the group call, talk to people, use video chat and have fun times, or just simply chat in the same group conversation. Skype is fun in my opinion, but it also has cons. First of all you will be isolated from the whole community and to be honest, that's not very good as a permanent solution. Second problem is (as Reuben already said) simultaneously running Skype and Ace of Spades. If you have good pc and fast internet that might not be a problem for you, but it is problem to many people with average/bad PCs. From my experience, it's not good to try to force activity on 2 sides in the same time. I'm assuming that you will try to set-up your IRC and get your members to use it. However, if you are doing that, your activity might split up between people that will use Skype and people that will use IRC and you don't want that to happen. It's best to decide which one you want to maintain. If you choose IRC, your best option might be Mumble for voice communication, because the whole community uses it too, you will socialize more easily, plus it's more lag free and most probably no one will have troubles using it and playing games in the same time. So, my personal option would be IRC + Mumble. If you're on IRC, you are connected to the most of the community. Well, that would be about it from the top of my hat, if I think of something else too, I'll update my post.
IGN:|SPQR|tin, tin