I can do this and I understood your requirements. I have an extensive experience in application development(web and standalone desktop) and some of my open source projects, similar to your requirement and others, are listed on my Github page(please check your PM for the link).
Even though I'm relatively new to Freelancer.com, I have worked as a Software Developer in the past, engaged in the role of developing a middleware stack for web services. An honest assessment of my past experience and expertise in this field will show you that this is the best deal you can get without compromising on the quality and reliability of the product.