Portable Battery Pack

Those portable battery packs are a rip-off of the highest order.
Go here:
http://www.apollobatteries.com.au/spec.htm
very bottom of page to the 862 or 882 Deep Cycle Battery.
The 862 is about $125 and the 882 about $140. These batteries are made by Global Yuasa in Korea and are the best value and quality deep cycle batteries I have found. You can buy a battery case without any fittings for about $20.00 from SuperCheap and fit a Hella 16mm Universal Socket (Don't use the 20c cheaper non-Hella units, as they are sub-standard)
Now for charging the battery, this is by far the cheapest and easiest to install and works like pure magic:
http://www.redarc.com.au/sbi.htm
and these can be purchased from Ashdowns, Ingrams, Baxters for about $110 incl GST. This could easily be made portable, but you will need to be able to use more than just a cigarette lighter plug. This unit will normally allow a charge of between 20 and 30 amps. If you are using it in the same different vehicles (say 2 or 3) you could use an Anderson Plug in each vehicle and on your unit.

Will you be using this on a casual basis in each vehicle, and for how many days at a time?

A 12v regulator for solar panels is a completly different kettle of fish to charging with an alternator.

Suggest you also look at the evaKool ED50 fridge. It is slightly dearer than the Waeco, uses the same compressor as the Waeco, but the cabinet is far superior in insulation properties and design, and can easily be opened in the back of most vehicles.
www.evakool.com.au

i think it was last month or the month before waeco were giving away a free portable power pack with a few of there fridges try a few difrent weaco dealers and see if they will do the same now if not try another dealer just play a few of them against each other im sure one will throw it in to get the sale i work in the auto trade and can get $200 off from our local bloke if i want one so i know theres a few bob in them just keep ringing and hastling

Thanks for your assistance, now have enough info to build my own portable battery supply.

If your getting a wet cell battery I hope your not intending to have it inside the vehicle while it's charging, as hydrogen is very explosive.

There are some sealed types of batteries that are supposed to be safe to charge inside vehicles or buildings.

Have a look at these AGM sealed batteries - they were recommended to me, but have not yet tried them:http://powerdive.virtualasp.net/products/Accessories/Batteries/