[sitkack]

When you find domains that contain useful information, crawl and index them manually.

[ccozan]

Indeed, the best solution.

Interesting enough, I find separate web crawling as a service and search engine as a service, but not both?

[AznHisoka]

You just described the Bing/Yahoo BOSS APi

[ccozan]

Allright, I forgot that ones.

However they are quite pricey. Maybe some solution that one can host himself is a nicer alternative.