150603 Valid Markup Search Engine

I am looking for a search engine script similar to Google, however the search engine will not index every page it will only index the pages that conform to the [login to view URL] validation standards. I need the script to be capable of crawling, indexing and validating sites quickly. The search engine should also be searchable in the same way as Google, using the various techniques such as plus signs and commas etc. The script must also be capable of accepting manual submissions. When a site owner submits their site to the search engine, the search engine will set their site as high priority and index their site, but only if their pages are valid. The user would have provided an email address on submission, and will be emailed informing them of whether they were successful in being indexed or not. A design is not necessary. I would like the main focus to be on the script itself. This is likely to be an on going project for a programmer as it is likely to have updates.