Hello there! :)
I'm a web crawling expert with several years of experience with developing various spiders, crawlers and bots and would love an opportunity to work on your project. This is not a hard job, but it can be time consuming and challenging if websites you mentioned have anti-scrape techniques "under the hood", so choosing the right man for a job is crucial :). Doing it with an iMacros is probably the wrong way to go, since it's not very efficient in terms of resources, speed and scalability and better approach would be developing specific scrapers for each of the websites. So, if you are interested in my bid or have any questions, feel free to contact me, I'd do my best to deliver high quality software that would suit your needs :)
Best Regards,
Srdjan