quality links come from quality sites and quality sites not always give out free links to other sites unless really really resourceful. focus on link building basics and get as much links as you can. blog commenting, directory submission, social bookmarking, rss submission, articles submission, setting up pages on social media sites like squidoo, hubopages, qassia, etc can get you lots of backlinks
I'd recommend NOT doing as many directory postings as Google doesn't seem to like them anymore and no longer even mentions the Yahoo directory in their information to webmasters.
There are many ways for obtaining quality and authority backlinks. One way could be contacting the SEO companies, the other one buying links from some reliable and powerful directories, sometimes writing great articles will bring many quality one way backlinks for you as well.