scraping and parsing google data like page rank and more for a domain

I need to scrape/parse some search engines related data for a given domain name(site).

I need

Google Page Rank (only for the domain name, not each pages).

Number of indexed results/pages (google, bing).

Number of Backlinks (google, bing, yahoo).

Traffic Rank (alexa).

Site thumbnail.

Could you provide me some pointers on where can I start? I tried to look around, but I was able to find only Google Ajax API which provides me number of indexed results only. That too expects valid headers which would mean, I have to be on that site, in order to make that work. So, I can't get data for any given domain.开发者_Go百科

Thanks

Their search API's are intentionally very limited so you will probably need to scrape this data directly from each website.