Does anybody know of any religious orders (brothers and priests) that dedicate their lives to serving the poor? I know there are the Franciscans, but I am looking for a different order.
Missionaries of the Poor
The Salesians do a lot of work with poor and at-risk children. You might give them a gander.
The Institute on Religious Life is a good place to search. This might be helpful.
Missionaries of Charity is my favorite order, but I know you already are aware of them.
You should take a good look at the Capuchin Franciscans. Always look at what an order really does, don’t just look at their website (i.e. some websites look better than others)