I run in a 16man HM DF/DP raid team. We are organized, have a custom chat channel and an email that the raid leader sends out every week. The thing is the team isn't a guild team. most of us are from all different guilds. we all just come together to form this raid team we call 'Blacksquad'.
Only thing is, is that we raid on the Empire side. Times are 8.30pm NZST Wednesday and Thursday.
This probably doesn't suit you, but just a heads up that there are groups out there like this, although not many of them..
Good luck finding one