LONG TERM SEO + LINK BUILDING FOR HIGHLY COMPETITIVE WEBSITE

I have a website in a highly competitive niche market of water filtration. My site is 5 years old with currently over 9000 visits per month organic searches. Current Google traffic is 4500-5000/mo. I'm looking for an aggressive company who can double that number witihin 6 months guaranteed (if you have one). I want a full service SEO company who can also handle PPC marketing. Service must include article creation as well as article submissions, directory submissions, social bookmarking & marketing, on-site and off-site search engine optimization. Please be detailed with what your fee will include. This is a long term deal if I like your services. If you have any guarantees, please let me know. I prefer pay per results web traffic if you offer it. Please send me your profolio as well. Include all fees including PPC management, monthly SEO Service, directory & article submission & creation. WHITE HAT ONLY