SEO + UI for my website

I need a full SEO & new User Interface design on the plug ins section on my site [login to view URL] It's for all the pages that in the plugins section. The SEO also include GUI on the pages you will provide me a report for things to change on the pages & i'll follow the instructions on your report. For example you tell me on your to change the title of the page from X to Y and my programer will do it. You provide me a sketch of GUI that should be on the pages & i'll do it. Before submitting a bid please answer these questions: 1. which guarantees can you give for your SEO (i.e double the traffic in mounth etc.) 2. How fast can improve site ranking 3. example of previous works