Design a UI for my website using Google Material/Polymer guidelines

A website with a specific layout has been built to conform to a specific set of functionalities. Now I need a UI specialist to come in help build the look and feel of elements in the website in line Google Material/Polymer guidelines. They will provide psd mockups, guidelines on dimensions and also show the developer similar components on the web, so they development team can base the code on the same lines. Please note: It has be responsive in nature and where diff layouts are required for diff devices, they should be provided by the designer.