Hi,
I read your requirement, you stated that you have projects and will provide design for each functionalities and I should write the back end code on PHP with CI. For your knowledge I would like to explain about my experience here, for more than a decade I am developing and delivering applications using PHP, JS, MYSQL with CI, YII and Open Cart. I am certified professional on PHP and MYSQL, even in the freelancer.com site, in the skill tests I cleared most of the technical exams with 90% and above. .
NOTE: Pay me 200 EURO, I will develop and deliver mock up screens as you are looking for this project.
Thanks
Paul.