I've already pledged in their kickstarter, but when I started looking for a guild when it releases (beta starts around September 2013, release around March/May 2014) I first thought about Gaiscioch. Has anybody looked at this game as a possible Saighdear? It's outside of the traditional Gaiscioch game but I know there are a fair number of M:tG players in the guild so there might be a good amount of interest in this (free to play) TCG as well.
http://www.kickstarter.com/projects/cze/hex-mmo-trading-card-game
For those who haven't seen it yet, Hex is a kickstarter project for the first MMOTCG (Massively Multiplayer Online Trading Card Game) that mixes MMORPG elements with TCG elements, kind of like mixing Rift with Magic:The Gathering with the added benefit of a card game designed from the ground up to take advantage of its digital nature. They've already reached their $300k goal on kickstarter and several of the stretch goals have been reached.
If you remember and enjoyed the old Shandalar game by Microprose (it was called Magic: The Gathering) from the 80's then you might want to have a look.