Best place to mount a diesel heater?

[Madmaninshed]

Hi,  we have a 1986 T25 1,9 DG watercooled petrol Transporter, converted to a camper, with passenger swivel seat, side kitchen unit and rear bed.  We just fitted a roof aircon system with heater, but the heater is crap, so I want to fit a diesel heater. I decided on a Vevor unit, but there seem to be two portable models (different shaped cases) and a basic heater with separate diesel pump and tank etc.  Strangely, the efficiency of each ranges from A to C, which I don’t understand, as they seem to use the same heater unit.  Can anyone advise whether a portable unit (which could also be used in our garage) or a fixed one would be best please, and where to fit it?  Many thanks.

[R0B]

I have my webasto diesel heater mounted under the glovebox.
And have the fuel tank sat in the spare wheel.

[Madmaninshed]

Thanks Rob,  I’ll have a look

[R0B]