My suggestion would be to get a high full door canopy with a powered roof vent as your basic structure. There really is no room to cook and sleep in the same space, so focus on sleeping and lounging comfortably inside and use an awning outside for cooking or recreating. My thought for inside is to make a U-shaped lounge with a table - When the table is lowered, it creates a bed. By using a tall profile canopy, you can make the seating almost bed rail high which will give your legs room to stretch, more storage under the seats and sufficient headroom to sit upright.
Run 12vdc and 120vac fuse panels inside the the canopy so you can wire individual circuits for your electrical demands. I suggest using a sealed AGM battery that does not gas off when discharging or charging so it can placed inside your living area. This battery can be charged off your truck or solar panels on the canopy. Having a battery will allow you to run interior lights and fans plus be able to use vehicle lighter plug accessories without draining the truck battery. Having a single AC connection with a distribution panel will allow you to wire outlets to the exterior where you plan to have your kitchen and inside where you can plug in chargers for electronics or a little ceramic heater. If you get really innovative you can even replace the roof vent with an air conditioner so you can get out of the humidity or heat in the worst part of summer yet still camp. When sourcing electrical parts, lean toward the marine/boating solutions that can handle moisture and vibration better than the residential counterparts.