Target Build Specifications

The Truck Cab:
The cab will be fitted with two air operated seats with arms and a further two seats behind them.
The cab will have its own diesel heating and an air conditioner.
I intend to remodel the dash slightly to accommodate a screen or two for internet satnav cameras etc, Controls for auxiliary lighting will also be sited here.
I am fitting a retractable tow bar system to the truck to tow a Suzuki Jimny (it's not easy to get into lidl's car park with a 12mtr truck)

Accommodation:
One fixed double bedroom, two fixed bunk beds, the ability to turn the seating area for 6 people into another double if needed. Plenty of storage under bunks.

Bathroom:
The bathroom will be a wet room design with a slatted wooden floor
Proper flush macerating toilet, Shower, Hand washbasin, Heated towel rail, cupboard for toiletries.

Kitchen Area:
Full size fridge freezer, electric hob and oven, microwave oven, washer dryer, coffee machine. I might fit a small dishwasher if i have room. Full height pull out food storage and plenty of additional storage. 
all cooking etc is by electric, for safety reasons i decided not to have gas on board, however, there will be a two ring gas cooker and bbq in storage as backup cooking.

Seating Area:
Seating for 6 people around a table that can be folded down to form a second double bed, storage under the seats.

Heating and Cooling:
The accommodation unit can be heated by both the air conditioner units on the roof or the diesel powered webasto dual top unit with hot air. Cooling is accomplished by the two 2.2kw air conditioners.

Water system:
There is 1000 litres of fresh water on board this is highly filtered for drinking and also feeds the kitchen sink, drinking water tap that is chilled, shower, hand wash basin, outside shower, and washing machine.
The hot water is derived from a dual coil calorifier that is heated by electricity either from the mains power hook up, generator, or the webasto unit. One of the calorifier coils will connect into the water cooling system for the generator thus scavenging the heat from there as well.

Waste Management:
The 200ltr Black water tank will hold toilet waste and can be discharged by a remote switch when needed.  The 200ltr grey water tank will hold waste from the sinks and showers this tank can also be discharged remotely. Both tanks will be fitted with fresh water flushing systems and a airator system to prevent smells.

Electric System:
There will be four sources of power, mains hook up, a generator, batteries and solar.
the generator will be 8kva Silent Diesel, the battery system 24v 1000Ah Lithium Ion and 2200 watts solar panels. When not hooked to the mains, power will be supplied by a 8Kw inverter system drawing from the battery bank, the generator will auto start and take the load and recharge the batteries if needed.
There will be USB charge points in the bunks the main bedroom and in the general accommodation area.
The usual mains power sockets and USB charge points in the accommodation area.

Entertainment System:
This will be a four zone system comprising of living area, bathroom, main bedroom, outside under awning, I might put one in the bathroom (she loves here music in the shower) I am using Sonos components i love the quality the ease of use, they will get there music from one of the two 12TB on board NAS drives that will store music movies and data, the same drives will provide movies and music for the 10" tablets in the bunks and the tv in the bedroom and main tv in the seating area. The sonos will also do internet radio when the internet is available. it can be controlled by PC, tablets smartphones or dedicated remote.
Satellite TV will be installed in the seating area and the bedroom with an auto-tracking dish system.

IT Stuff: A router system allowing 4 separate sources of internet, cable, 3G, wireless, or satellite. these sources can be combined for extra speed or simply used as failover, depending what is available. this will be installed to feed the internal systems and wifi devices inside and outside the truck.The truck will have its own PC for internet access it will also be connected to the on board power system and all the heating and cooling devices for control and diagnostics.

All of the hi tek stuff in the truck is just for entertainment or comfort, nothing is mission critical.
All the mission-critical equipment is using the "double redundancy" theory.