Twitter Username Scraper

I need a Twitter scraper that can scrape all the followers of a Twitter account i enter. For example, @cnnbrk has 8,912,380 followers, i want them all to be able to be scraped. The accounts I need to scrape have millions of followers, so It cant use the api and cant be browser based as this is to slow. I need to be able to save the users to file, also i would like the usernames saved to a temp file in case of crash. I have had bots coded before, but when they reach 1 million followers scraped they slow down to scraping 1 follower per second with is to slow. I need the bot to be fast and be able to carry on at the speed until finished. I would like the source code to be include due to how ofter twitter updates, but this bot will only be for my use. The bot can be coded in any language, VB, python or php etc. I would like to view the bot working fully before payment is sent. Thanks