Working on mine too, but I don't think the omega items are as much of a problem as the 450 rainbow prisms requirement, or the 950 element orbs.
Is leeching magnas already the best way to farm those rainbow prisms? I'm still only at 95, and that's from all I've played till now.
No doubt. Rainbow crystals are commonly the bottleneck for first gw char. Doing a lot of leeching during magnafest will help but you'll probably end up wanting to do the daily Thursday dungeon. The hardest one (which isn't that hard) can drop 1 crystal. It also drops lesser crystals that you can trade up for rainbow