Lots of advice here, not much useful. Be sure to budget for Microsoft Office (Word/Excel/etc) if the kids will need it for school. $200-$400 per machine... I would contact their teachers/school to see if it is needed, and if they have student discounts available for software and/or hardware.

It might not be cheap to get them all up and running. But hey, kids ain't cheap. Feel free to PM if you need some specific advice.

NitroxBoss here on the forum owns Action Computers http://actionpc.com