Google Mass Search is a small script written in python to get large number(as you need) of urls from google search results of a specified string. It is really simple to use but fast & powerful.
You can specify a search string, no. of results filename, and some optional fields. GMS retrieves all the required links in a few seconds and save it to the file. It also eliminates the redundant links.
You can also apply filters like links containing a given string or not containing a string....