I guess I would vote for Belgium or Holland as the gathering sight since I have friends I'd like to visit there. If not Austria is fine. For me the closer to Spain the better since the farthest it is away the more it costs to get there. Flying is out of the question and my 25 yr old jeep is a bit of a gas guzzler!
Like Andre said, the important thing is to have a meeting, every year if possible. Its obvious that at any given meeting someone isn't gonna be able to come, but thats just life, isn't it?
I hope that in 2 or 3 years we are able to host a meeting in Spain!
love , RIKKI