I'd encourage you to consider Heralds of the Voxyn
for your imperial toons. We're a fun-first, friendly guild, and we do both progression raiding and "first-come-first-served" casual runs that are open to anyone who meets a few (minimal) gear requirements. We have Vent.
We do most of our runs in the usual evening hours, but we have a contingent of folks who work night/swing shift and if we get enough people interested we try to do casual runs to fit their schedule. For example on a Sat at 7:30am we have 10 people logged in, and often do runs on Sat. afternoon (and have done late raids starting after 9pm, for your nights off!).
Feel free to register on the Web site to check us out, or drop me a mail/tell ingame.
Animae, Senior / PR officer
(aka Animara, Odani, Vi'ta'ra)