Here are the issues:
Keeping noseweight at a minimum.
At present 65kgs. Very close to maximum. So the idea is the spread the weight about a bit. Perhaps some in front of axle and some behind.
This means putting the heater at the rear offside under the single bed compartment.
Easy routing for exhaust and inlet. And away from doorway and awning.

Next, the fuel supply. The supplied 10 litre container fits suitably in the locker over the A frame at front of caravan. This means piping diesel approx. 14 feet. So where's the best place to fit pump? Near tank or near heater? Or it doesnt matter? If near heater it keeps all wiring at rear. Which l prefer.

If l put pump next to diesel container in the front l will need to extend loom and buy addition ID 1mm OD 4mm hard nylon fuel line (from where?). Plus the dreaded tick will be next to the main bed the other side of 25mm of plywood.
Or l could go with this set up using a five litre diesel can opposite side to diesel heater. Then, apart from sourcing 12v power amidships, everything is aft of the axle and less noseweight. All wiring nearby too.


So in a nutshell; supplied 10L tank up front. Heater in rear. Extend fuel pipe. Where to put pump? Extend loom.
OR.
Heater and 5L fuel can at rear either side. Pump near fuel or heater?
Where to buy extra diesel nylon fuel line?
Your views please.
Regards
Stuart