Off the top of my pointy little head.
What is your intended use? Use for Booster Heat and Pre-heat only MAY not be too bad control wise by using DIY methods. Integrating into the ATC/OEM controls will be more involved.
Basic Installation.
Easy things.
Grab the OEM Espar electrical connector with reasonable wire tails.
Grab the OEM holding sheet metal U shape channel. One could be fabricated or perhaps some Stanley hardware L shape brackets could be adapted.
The inlet air and exhaust shouldn't be difficult.
Hose can be used to tie into the coolant circuit. When I reinstall my repaired Espar I plan to use hose. I anticipate that a 3/4" 90 degree elbow will be needed from the Aux Elec Pump outlet to the inlet of the Espar.
https://sprinter-source.com/forum/showthread.php?t=50483
A 25 amp dedicated 12 volt supply will be needed.
2 ea. 12 volt enable inputs will be needed to power up the Espar.
For other than Booster Heat mode a method to power the Aux Elec Coolant Pump will be needed.
A bit tougher...
An additional fuel tap from the tank will be needed.
Possibly the MB bastardized Espar controls will need to be satisfied. I'm not certain what that will entail, if anything.
vic