Is a 120cm double washbasin sufficient?

120cm tall enough for a single but wide basin.

In principle, can any built-in washbasin be placed on a foreign base cabinet if the dimensions fit, or must it necessarily come from the same series?

I don't think so. The washbasins have different shapes. Accordingly, the washbasin base cabinet is shaped.

So, since time is pressing and the delivery time for a Pelipal would be quite long, I am now considering installing two single washbasins (each 60) with their own cabinet. Is there anything against that from your point of view? Well, visually I would prefer a block, but actually two singles are more practical..?

2 sinks on 120 cm width ... why necessarily 2 sinks when the entire area is only supposed to be 120 cm wide?

Just take a wide washbasin and two faucets that are mounted in the wall. That would be a good compromise: nice appearance with a large washbasin, but still two washing stations.

There is actually much more space available, gladly more than 120 cm. That's why I asked...

: What do you mean, in the wall? I am no longer installing concealed fittings – the room is freshly renovated and finished. Or do you mean a continuous wash basin with two faucets in the sink?