Pagerank / inlinks / Alexa rank bulk checker

I need a PHP script that is capable of checking lists of urls for Google pagerank, links pointing to the url on both google and yahoo and to grab Alexa rank for the url. This will be run daily and the number of urls to check each day will be 100-5000 (avarage is <500) so there is need to use some kind of technique (proxies?) so the search engines dont block the IP. It should also be multithreaded, so it is fast. No GUI is needed as this will be run as a cron-job. It should look in a specific Mysql table for domains that it havent checked and save all info to Mysql. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform PHP / Mysql