Methinks you need to build the DOB first and then consider what you need to transport it in. That will dictate what other gear you haven't even thought of yet that you will need.
Basics: 12" f5 Dob OTA laid down, so need at least a 6' long trailer, longer is better. Single axle as it's not too heavy. I reckon you could do a drop down bunk bed on other side over equipment save carrying/setting up tent. Side awning so you can sit out waiting for the rain to stop

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Deck chair and chiller ( Esky to you guys ) for a few bevvies
Mobile man cave !! Cool as !!