SEO Expert for small company

Looking for SEO Expert who can get my existing site (3+ years old) to the first pages for certain keywords on MSN and Yahoo (especially MSN). It's already near the top on Google, but if you can improve on that then that's great. I have experience with link building and optimized my homepage for those keywords, so the SEO Expert should be able to see what is(are) preventing the site from listing on MSN and Yahoo, WITHOUT losing my existing SERP in Google. I want to avoid having to place paid advertisements -- I've seen other sites done it without them, so it can be done. I know SEO will take time, so PM me how long you think this may take. Several or couple of months OK. Will finalize payment once the goals have been achieved and Google SERP maintained or improved. I would like to see a portfolio of similar jobs, if you have any. Site is hosted on Linux server via HostGator. I will give the keywords I need to be ranked on the front page for. Please send PM with rates and experience. Thank you in advance.