Here's some guild options for us, all 18+ casual progression/raiding, non RP:
Flux Capacity: http://www.fluxcapacity.enjin.com
Gravy: http://gogravy.org/
Crimson Wing: http://www.crimsonwing.org/
Dominion: http://mmo-dominion.guildlaunch.com/
Do you guys have other guilds for suggestion or other options?