Design a Flat, Clean Admin Panel for Web App (Need Basic Design, and HTML/CSS Skill)

I need an admin panel made to manage members & memberships for a non profit I assist. It can use bootstrap and we are after a design that is responsive, flat, and clean. It will have a left Sidebar Nav, and the "content" areas are mostly forms or tables. This admin panel will be used to manage a groups members, renewals, plans, etc. So you have a dashboard with a few snapshot elements; various forms for Creating / Updating group info; Report tables(note, i want tableless) to list members, with a few filters; Some basic Signin, Signup, Forgot PW type modals, An email Template (simple header, html lite text body with a button, footer) ; This is likely going to be an ongoing job. However, please estimate how much to get the basic templates down (listed above) with Flat styling.