Local group idea:
What about donor coalitions instead of donor lotteries?
Instead of 50 people putting $2000 into a lottery, you could have groups of 5-10 putting $2000 into a pot that they jointly agree where to distribute.
-People might be more invested in the decision, but wouldn't have to do all the research by themselves.
-Might build an even stronger sense of community. The donor coalition could meet regularly before the donation to decide where to give, and meet up after the donation for updates from the charity.
-Avoids the unilateralist's curse.