Hi
After seeing your revised User Requirement, then the project is actually bigger than I thought. The data scraping shouldn't present too much of a problem, nor should running several threads.
I'd code the site in PHP, using the CodeIgniter framework (or maybe just bypass a framework entirely, since you don't need many views at all). I'd set up the database as MySQL. The scraper would use cURL and some kind of DOM walker. Probably the admin pages would be ajaxed.
I think this would take about 10 days.
I'd still definitely need to see the site that needs to be scraped, though, since this is essential to this project. If it's too difficult to scrape, then the whole thing is a no-go. Could you please send me a link to the site you want to scrape?
Best wishes,
John