Adwords Keyword Tool Scraper

I need a scraper for the Google Adwords Keyword Tool: [login to view URL] Using something like curl is fine. This scraper must: 1. Spoof a common browser as its useragent 2. Scrape keyword results for a specific keyword, getting keywords, advertiser competition, and search volume 3. Recursively get keyword results for each returned keyword. In other words, enter each keyword from results into the keyword tool and get results for that keyword as well. The script must have an option for how many levels deep to scrape keywords, and it should stop when no new keywords are returned. 4. Save resulting keyword list on the server as a .csv file in a specific format. 5. Deal with CAPTCHA and session timeouts. It doesn't need to solve CAPTCHA obviously, just detect when a CAPTCHA is required, download the CAPTCHA image, allow the user to enter the CAPTCHA and post CAPTCHA. More specific details will be given to the winning bidder. Please describe your previous experience with writing scrapers in PHP in your bid.