What will be the internal features of your non-profit organization website?
How many pages and what are the pages you need?
Do you want responsive design so that the website is view able properly from all the devices like phone, ipad, laptop etc..?
Do you have any reference website in mind what you like most for the design?
I have very good experience in website designing and development using WordPress, PHP, MySQL, Ajax, HTML5, CSS3, bootstrap,jQuery, JavaScript etc..
I can give you very good design and well coded responsive works. Website will be W3C validated, cross browser capabilities and well developed.
Lets discuss more details..
Regards
Esha