I think it is awesome that you are working at donating yoyo's for the kids. There can never be enough people like you. I can't believe there is no formal yoyo drive in place already! I work in the juvenile criminal justice field and have also been seeking donations to help our yoyo club get off the ground and to be able to get free starter yoyos for kids joining the club.
My experience has been very similar to yours. I've had the most help from local businesses as well as Yoyofactory. While many criticize Yoyofactory for being to large, they are in a position to help, and choose to do so. That is very commendable.
I would love to get in touch with you and see if there is something we can do for future years. I've found that finding donations has been relatively easy part. There are many organizations/businesses out there with funds to help kids. The biggest problem is getting yoyo's into hands of kids who will actually be interested and put them to use. I am also an adoptive/foster parent and my problem with toy drives around christmas time is the impersonal nature of the gifts. The amount of money and time put into these gives is immense, but the reality of foster care and troubled homes is that most toys are broken/lost/misplaced within a week after christmas. A yoyo would get tossed aside quicker than you can say merry christmas. very sad but true.
Giving yoyo's away in conjucntion with demonstrations; non-profit clubs that support disadvantaged youth, People doing yoyo seminars/classes; And local contests that help promote competition and progress are where we need to focused with the drives. While the cheaper yoyo's are easy to get in bulk, I'm finding the need for more pricey metal yoyo. As the kids advance, you have some kids that have money to buy nice metals and others that never will. Please send me a PM and we can exchange personal information if you're interested in collaborating and getting something started. One of the reasons Duncan was sooo successful is that they had so many yoyocontests all over the country. Every town had a yoyo champion. I really think there is something to learn there. While yoyocontests today are very impressive, thier is a huge void from beginners to pro!