In 1/700, you might try contacting this guy:

https://tlarmodels.com/

He offers one lighthouse kit, and includes lighthouses in two of his other kits:

https://tlarmodels.com/ols/search?keywords=Lighthouse&sortOption=descend_by_match

This from 2021 shows he used to offer a Saint David's lighthouse kit:

https://modelersalliance.org/threads/1-700-the-deep-dive-boat-corsair-and-st-davids-lighthouse.155835/

And that shows me that he might be interested in custom work...

As you can see, his work is "on the primitive side." He would say it is "basic," and expect you to put in skill/effort to produce the results you desire.

FWIW, HTH