I know this is about highlift jacks, and that they
are usefull for more than jacking up your car.
But,
I've just recieved a catalogue from quadratech and found a new product that wold suit you JK guys.
It's a moulded "base plate" for your original jack, they state that it will lift your car high enough with up to 33" tyres. The big plus is that it is designed to fit into the underfloor cargo area in the back of a JK.
Thought it was pretty cool.
Sorts out the storage problems and good enough to change a tyre.
found the link, up to 35" tyre..
http://www.quadratec.com/products/92200_700_07.htm