Hi Ian
We have a 2013 Jayco Penguin OB. We have used it quite a lot for free camping, and for this we have:
Solar panel installed on the roof (120w)
2 100amp/h batteries plus a small inverter (300w) for charging laptop and phone etc
We also have a generator just in case
You should ensure you have at least 1 12v and 240 socket outside. If we were doing it again we would probably put a second 12v outside.
We have twin water tanks installed plus a 12v pump and a tap on the A frame.
We have a Fiamia wind out awning plus sun blocker, the kitchen mate on the opposite side, and end awnings at either end. This really helps with keeping the sun out, great for privacy and also keeps the rain off the canvas.
We didn't get the electric roof winder, instead we use an 18v drill to wind it up plus letting down the stabilizers
We have 1 9kg gas bottle which so far has lasted approx 40 nights away with half in a caravan park and half free camping. I have installed a gauge on the gas bottle to let me know how full it is (or isn't). Still over half full. However, when free camping we do most of our cooking over a fire if possible, so the gas is used for the fridge only. We also heat our water over the fire for showers etc using a Hillbilly instant hot water system.
We carry a small spare bottle of gas as a backup.
We had a gas bayonet installed on the A frame, but have yet to use it.
We originally had a Jayco Finch but got fed up putting the beds out and changed to the Penguin. Much easier and quicker to set up. We also find the Penguin easier to pack as there are no beds in the way, and fridge is directly in front of the door so you can easily switch from 240 to 12v just before you leave.
So far we have found the solar power to be excellent - we have had phones laptops and lights running off it together with no issues.
We found that we never sat at the dinette table - so we drop this down into the bed setting and put up folding shelving for clothes and just use that area for storage as so far we have always sat outside under the awning.
Obviously everyone has different needs, but we would never consider a slideout bed type again over the Penguin.
Hope this helps
Brian