Hi Starry,
Ambitious trip you aim to undertake. Firstly, I'm assuming you're no dill when it comes to the Kimberly!
You're right about the typical GSO/Bintel dob being too sensative. However, if you are prepared to take to it with a "hammer and saw", you should be able to fashion yourself a compact and durable compact dob.
The 10" dob I made has a pedigree of the such. It was fashioned on a design that saw its forefather do a similar trip as you are planning, right here in Oz:
http://www.atmsite.org/contrib/Ravneberg/alice/
I've seen this design taken upto a 17.5" puppy.
My 10" has been on trips with me too by 4WD. Of course, you will need to collimate regularly with all the bumps, but the design is rugged. Collimating is not a big deal, and is done quickly. And if you at least are able to make a decent dust-prove bag to seal your scope, you will be richly rewarded with the views. I've included a couple of pics of mine.
Dust will be the worst enemy you will have. However, if you can dust proof as best you can, a 4" to 8" Maksutov or Schmidt Cassegrain scope could be your best options if the above rebuild doesn't appeal. Have a look at the Andrews website for their Celestron range as their prices fall within your parameters.
Bon voyage!
Mental.