Hey there.
Happy to have your attention, if only for a brief second.
I read all the project info - good stuff. I know I don’t have so much jobs experience here on Freelancer, but I’m confident I am well qualified to undertake the task at hand and I can provide you with top notch material based on my C#, Software Developer skills that will fit your needs and last but not least I have built something like this just not so "full-option" .
Rather than bore you half to death with some "tousands kilometers" length proposal I will summarize all and I tell you just some of my skills relevant to this job. Among others skills I am a C#, C++, Java and SQL expert and I have made many greater websites and softwares for other companies, some built from scratch like this project and some just edited at the design or functionalities parts, as you can see in my portfolio.
Even though those skills can't be seen here on Freelancer I worked a long while on the older Elance and you can see my Elance skill sets on my profile.
I can work anytime you need me and I am also a good designer, as you can see on my older Elance profile I am an Photoshop Expert and I think this skill will help me a lot to make an awesome looking software if needed.
I think I can finish this project in maximum 11-12 days of hard work because it is a complex software and can't be made in such a small time as the others mention, in my opinion.
Good or bad, I'd love to hear from you ;)
Hope we talk soon,
Erik