Automated site links Crawler

I need a special web-site[bbs] links crawler to automate logging in, search form filling & save results (extract selected types of file links from search results) plus downloading all files with extracted links. Task must be fully automated (to run on dedicated Linux VM with cron)
Plz end-developers bids only! There will be a lot of tech questions and talk so if you're a manager plz don't waste your time(you will fail definitely) Thank you