All of those suggested options for Digital Asset Management (DAM) are of the installed variety; when dealing with a library of this size, the non-profit might want to look into a hosted (Software as a Service) solution like the Widen Media Collective. With a hosted DAM, the non-profit you volunteer for will not have to worry about IT and server costs, setting up the DAM, purchasing software upgrades or purchasing new servers for increased storage - they are all included in the hosted subscription, along with support, training and expert assistance.

Widen is a leading provider of hosted DAM services and what you are asking is similar to what I have heard from other people at non-profits that Widen works with. Widen also has special pricing and terms for non-profits. Take a look around the Widen website; if you see a fit and want to schedule a brief online demonstration, follow this link and request a demo.

Good luck on your search!