Purchase/equipment advice first caravan two persons

Hello! I would like to buy a new caravan for trips with my friend through Europe (in summer at the same height or north and in winter to the south).The towing vehicle is a Chevrolet Epica with front wheel drive, 143hp with an unladen weight incl. faher of 1560kg and has a trailer load of 1600kg, which however should not be used to enable sufficient climbing ability. Requirements for the caravan: 1. cost-effective and economical in operation 2. easy (also suitable for large climbs), furnishings rather spartan, thus no heavy furniture 3. well isolated, as dense as possible, in order to be able to use the car also during the transition season and in the Southern European winter 4. well suited for autonomous operation, as mainly no campsites are to be approached 5. 100km/h registration and as safe as possible also on medium mountain and alpine roads 6. Operation as many consumers with gas as possible, since independently of the electricity grid is to be camped (eventually gas refrigerator instead of compressor, gas convection furnace and gas heater) 7. possibly similar to Deseo Box only slightly larger but with shower etc.