I know from and in NRW that these sell houses including suitable plots of land.
Are there any other providers who offer a land service and can be recommended, for example ?
Just the fact that you mention Viebrockhaus in the same breath as Allkauf Haus and Massa Haus shows what an easy target you are for con artists.
I suggest you also take a look at the posts by @11ant on the topic "land service" and "short sale."
I recommend looking up with the keyword "11ant short sale" to see how the con artist scheme works that might be attempted here. In summary: one searches the land offers for a cheap , then pretends to own it, calculates a total price with the list price of an also very cheap house and scams a construction contract with this "land service" (but is not a builder themselves, only a commission broker for a general contractor). Town & Country is indeed an affordable home provider, whom you don’t need to outright warn against, but unfortunately: they belong to providers whose house models are gladly misused as bait for such fraud schemes, and (like and other league mates) to those whose partner network is now, let’s say, "mixed."
The probably still most recent summary of findings on the search term "11ant short sale" can be found here:
Viebrockhaus would be comparable to Gussek Haus (different construction method, same clientele) and builds turnkey premium "solid" houses. Allkauf Haus and Massa Haus are expressly specialized providers of prefabricated timber frame "shell" houses. So you already took the most awkward possible comparison at first glance, because either you are privately insured / above both assessment limits / company car employee with salary conversion (each linked with AND), then Viebrockhaus, Gussek Haus, Weberhaus, Bien-Zenker and similar. Or your household budget only works if you put almost exclusively store brands in your shopping cart at the discounter (then Allkauf Haus, Massa Haus, or similar). But with shell house providers you have to be really skilled in DIY, otherwise you save nothing. Or as a builder you belong socially to the still 80% broad middle class, then there are other, more suitable building partners in large numbers for you.
In any case, you can get help here – the better we know the "building family Haus_Bauer," the more targeted the advice. By the way, you also find tips here on the keyword "11ant Barthel" for your own land search. NRW is large, narrow down the desired region more closely.