Please help me look for something similar to this...

[Beakyok]

We are in the process of getting our downstairs cloakroom changed. The space available for the vanity unity is about 40-50cm and I have fallen in love with this mid century look unit. However, it is way too big (and probably way too expensive!). Does anyone know of a suitable alternative please?

auction house you would probably with patience get a genuine 1950s unit for a fraction of that price

Why don't you buy a wooden unit and a sink and get your plumber to cut a hole and set the sink into the unit?
The photo you've shown is just one where a company have done something similar. You can do it yourself without having it ready made.

Superfront

www.bidspotter.co.uk/en-gb/auction-catalogues/thimbleby-and-shorland/catalogue-id-ibts10225/lot-490bd350-9d15-4f66-832c-abd800b8ba27?utm_source=bs-bespoke-auc&utm_medium=email&utm_campaign=thimbleby-and-shorland&utm_content=ibts10225&utm_term=2020/06/21

Thanks, great ideas.

If you google scandi sideboards there are loads under £200. Especially on wayfair and dunelm