Create a simple event attendance responsive website

I'm using an existing website service (Example event: [login to view URL]). Simple but effective. The site has been sold and the new company doesn't want to continue offering the service. I need you to build a copy of the website offering similar features - design must be slightly different though in order not to violate any rights. Site consists of frontend and admin page. Purpose of the site is to create an event (admin feature) and for users to mark whether they are attending or not attending the event. A comment can be made as part of the attendence / non attendance and you can delete your attendance again. This doesn't require login. Frontend: 1: Logo 2: Banner 3: Event date and description 4: Input field (Name of participent) 5&6: Name of participent depending of which button pressed (attending / not attending) 7: Input field for comments 8: Functions (mail notification signup, "same answer every time" and admin page) Backend: 1: Logo 2: Adminbanner (static) 3: Edit event description and date 4: Change frontend banner and color 5: Put a deadline for signing up for attendance 6: Administrate email notification / signup 7: Delete names and comments from frontpage 8: Should there be a link on the frontpage to the admin page? 9: Link to the frontpage There are additional features in admin page but we don't need to create those. The site can be based on any of the open source CMS like Joomla, Wordpress etc. but can also be developed from scratch if chosen.