Seo for my website - open to bidding

Hello, I have a site [login to view URL] that I am looking to improve my organic rankings for certain keywords. We basically offer AdWords currently to achieve a Google Placing for our clients. However, I want to move to more and more Organic rankings for the clients. I am looking to partner with a provider, but because this will be a value ad to my clients, I need to have a fixed price going in. Do you offer fixed pricing on keyword rankings? Do you offer any sort of guarantee time frame for the keywords/keyphrases to appear on Google first page? Please ignore the info below on the project... I am just enquiring as to whether you do offer a fixed price, and/or a guaranteed time frame? Many thanks.