At least a couple of us raid with various groups in the Older Gamers guild. They have established raid groups, and casual raid nights for guild members, running at NZ and Aus optimised times. They have an minimum age entry criteria of 24 (IIRC).
They run on The Harbinger: http://www.theoldergamers.com/forum/har ... id-groups/
And Red Eclipse: http://www.theoldergamers.com/forum/red-eclipse-eu/
You might need to sign-up to those forums to see all the details and subsections.