Newbie needs help

Hello. I/we would like to buy a WOMO, so around the 6000 Euro can cost the part. I looked at ebay, mobile, scout24 and dhd24. There are some that come into question, but since I have no idea, I wanted to ask a few questions. Maybe I get some decision aids. Many that I have seen are built on the Ducato, like the Peugot, I think with which typical faults one has to reckon with with with these types, what should one pay attention to. Rust!!!! ufbauen, there are tens of thousands of different, of which one should leave the fingers? or which are particularly good? To the engines, 1,9 l , 2.5 l with or without turbo, how much PS/Kw should one take ? Which years of construction, prefer a 95er with 250000 KM. or an 88er with 125000KM. At what intervals should timing belts be made, coupling, axles etc. How much liters of diesel a WOMO consumes so about and what it costs in tax and insurance( depends on the % ) but so much so. Thanks to Svenson