http://www.kempower.be/opel/omega.htm
Stage 2 kits, also seems to have ECM, camshafts, exhust, and other stuff.
The stage 2 kit seems to be a little pricey, I converted from EU to USD and it's like $2700 not including shipping.
but the Stage 1 is not that much differece in HP/TQ but it's like $1000
Will try to find more.