I came to know a very friendly company who have very nice solutions for the darkroom.
I have asked for a quotation for this article https://www.deitenbach.de/film-und-fotobecken.html
and they returned with a four digit number in euros just for the plastic basin.
I may afford it but given that I do not work so often in the darkroom the above article is kind of a luxury for me.
So, I am turning towards DIY shop for alternatives and came with the below basin.
I found something like the professional tables in your first link on a local auction site for €300 brought to my door. Included was a separate 90x80cm basin.
Those tables are offered at a regular basis. Just look out for them.
Regards
Frank
Many of us build our own darkroom sinks (sink = Waschbecken/Becken/-becken) out of plywood. There are lots of designs, but all you really need is a rectangular box with a drain at one end (make sure you tilt the sink a bit toward the drain corner ) and some legs. Heck, you could even just set it on a table. The problems with individual sinks would be that it's awkward to move things around and you can easily drip between sinks.
My darkroom sink is 3 meters by 1 meter with storage underneath and cost me just a few hundred dollars. Even with Germany's more expensive materials, you should be able to build something that would fit your space exactly and work really well for a few hundred Euros.
You need plywood, glue, screws, saw and screwdrivers and some marine paint and your set.
A large sink, big enough to hold trays is the most convenient but a counter with a smaller sink is workable. I use single basin kitchen sink set into a counter in my current darkroom set up.