Another vote for a FirstWatt amp (if you want to go with a separate amp and pre). With your Omegas, I'd look at the F2 or F2J. They have a fuller sound than the F1. These are also current source amps which gives you the wiggle room to adjust the sound of the bass and treble (see the 6moons reviews of the F1 and F2 for details). Note that since they are Class A, the FirstWatts will run hot.
Another vote for a First Watt amp. I'm currently putting a M2 through its paces, and let state that this may be the most enjoyable amp I've ever heard. The nice features about the M2:
1) Increases power to 40 wpc at 4 ohms
2) No feedback whatsoever
3) Uses a passive transformer gain stage
It's got all the virtues of tubes, but no drawbacks, and it's quiet (compared to tubes, that is).