Innamincka add-ons

Following on from a thread a little while back, I'm looking for some comments about destinations/route on the way to the Innamincka gathering.

The base data: just myself and our 8yo (Liam) travelling, need to be back on the Monday after the gathering (need to fit into Vic school hols this time) so a window of 2 weeks Melbourne-to-Melbourne. Driving an NP DiD Paj with 600km dirt road range, water and supplies for 5 days between stops, AT tyres, UHF and possibly satphone plus basic recovery and full first aid etc. Whilst taking into account the reality of "sole traveller" limitations, we camp around 30 nights a year so average offroad/semi remote is ok for both of us.

Ideally we'd like to go to Coober Pedy, Birdsville and the Innamincka surrounds (Coongie, Cameron Corner and the Burke & Wills links). My gut feel is that Coober Pedy adds too much distance for 2 weeks. Does it make sense to include Birdsville in an Innamincka/Birdsville duo or should the trip be something like meandering through Broken Hill (is there a fossicking experience for Liam to replace Coober Pedy?), then Cameron Corner and a week around Innamincka? Were were in the Flinders Ranges in 2006 and don't want to go back yet.

All suggestions much appreciated.

Adrian