The bill that best meets your needs is the one your group decides would be of most interest, and that which the group feels it would do the best job of either defending or reforming. That is not a question we can answer for you.
Regarding the issue to address and how to do it, the first step is to research to find out what the issues mean. There are a number of really great questions to guide your thinking in Section 3 of Chapter 30 in the Community Tool Box. The entire chapter has great guidance for advocacy campaigns so you might find a lot of other helpful information in there.
I hope your project goes well!
The Community Tool Box Advisor