18, check last image.
Almost, that image shows 18 more available with 2 taken.
Just a quick update, first tests with Barnabas showed great speed and stability. Despite some people seeing high ping time on the server list, latency is drastically lower when in game. With 140k bricks and 20 players my ping was sitting nicely in the 90-120ms range from the UK which I consider to be brilliant.
The next step is to put a DM server up for testing. This will probably happen in the next few days and will most likely be hosted by Bushido.