Not for Profit (Charity Org) Website in Wordpress

We want to rebuild an old website and make it into a modern WordPress website with good graphical representation for a Not for Profit (Charity Org) Website. We are looking for CLEAN, EASY TO USE AND SIMPLICITY Everything in terms of contents( past events, pictures, texts, press release, descriptions, vision, mission etc) will not be changed but only transferred to the new site. All the logo and banners will be changed to topnotch and quality graphics. Here are the few samples of a great nonprofit website we like: [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] Our main event coming up soon will be the first thing that will pop pout everything someone logs in (like a popup).