Hello,
I am electronics engineer, currently working on my diploma. I am new to freelancer, so we can make a deal for discount by your choice. As low as you like (even for free), because, I need some reputation on freelancer.
I have a lot of experience with Arduino. I have Arduino nano, so I can test develop during process. In the end if you like, I can design you custom PCB for less cost than all the components you have on list (Arduino nano is expensive).
I am well organized person, so you won't regret if you assign me this job.
Regards,
Blaž Mandl