I'm also looking at doing a Sydney trip. I emailed quite a few travel agents in Libya, but only 1 got back to me and it took them 10 days.
Thought I would share the info.
www.libtratours.com offer a 3 night/4 day tours for 650 Euros with a 50 Euro single supplement. It seems pretty inclusive - visas, transfers, all meals, tours of Tripoli, Leptis Magna and Sabratha. 4* accomadation.
Now I actually have a proposed date for this, I will step up my efforts. I think I'll try faxing before I resort to telephoning them though.