I would consider donations to CDL first and then an org like TDI.
I didn't know school systems would accept outside computers? I have friends that work in IT in public schools and TBH they're pretty much rolling in money. They have storeis of days where they have to spend like $300,000 by the end of the day. It sounds like it's not managed very well, but money doesn't seem to be an issue when it comes to hardware. Plus if you are supporting an org, having standard configurations for automated deployment and stuff is a big deal. Now if you could get the computers in the hands of the young children that are from lower income/troubled families, that seems like it would be cool. No idea if the parents would allow it to stay or pawn it but it might open the door for kids to mess around and get curious about computers. Self teach skills, etc. - Ethan