adding members to my website

I have tried to hire many different types of people to get members to my website a strategist, an seo guy and an assistant they have not been able to deliver what they promised or have been "flaky". I am finally ready to find someone to be able to get members to my website. I have done the research and I know that it is a profitable market but I just need someone to deliver what they promise for a reasonable price in a reasonable time frame. My short term goal is to get 300 new members in the next 3 months. I do not want to use black hat methods and anyone who does I will immediately terminate their contract. This person does not have to do everything. We will work in conjunction where I can help post, find guest bloggers, post status updates, and help with the design. I do not need any SEO because I already have a good SEO guy so if all you do is SEO then this is not the job for you. As for compensation, I can negotiate I would just need proof of that your price is worth it and you can produce results. If you are interested please respond. I look forward to find the right person for the job.