Looking for a Google clone script

Is there such a php + mysql script that does what Google is for? So my users can come and search the web? I suppose this would need a huge database but is there any such clone script available that does the crawling and indexing automatically?

I’m not looking to crawl or index the entire web, just some selected sites in a specific niche of course. The users would then come to search for a key phrase, the results are ordered by relevance, etc.

Whats your budget mate ?

Kindly contact me with your expected budget via profile page contact form, I can help you on this.