it's a great mod, just not cheap or easy
have a read of my conversion thread.....
viewtopic.php?f=88&t=7102
seeing as you will be converting an astra G you could simply use the astra H gear linkage, you would require the astra H sri turbo driveshafts (the vxr drive shafts require vxr hubs and your abs would not work with those hubs), you would also need the astra H gearbox mounts