Tom,
I hardily agree with you about having the capability to do a tire change. We are also frequently out of cell coverage and I do have Verizon and a 3 watt repeater.
Now, to your case, even if you do find the jack that someone said should be there, see if you can find specific instructions on how to place it. When you know, or think you will buy a jack, go to the house of a friend that has a big compressor and let the air out of a front and both rear tires and make sure you can use the jack from an "on the ground" condition.
Also, carry some blocks if you are not carrying any for leveling and figure out what it takes to shore up the coach while on the jack. Many hydraulic jacks leak down.
Matt - Has a coach for which the OE jack is not real good.
