How do I choose a lab to rotate in?
I would focus on choosing an advisor and a project as your priorities. These will be the two most important decisions you make as a graduate student. The project you pick will be your preoccupation for the next five or so years, and your advisor will be one of the most important figures in your career. New skills and funding are secondary to these, and the issue of prestige almost shouldn't enter into your decision at all.

In particular, I would actually argue that it's not just choosing an advisor; it's choosing an advisor and a group. You will almost certainly be spending more time with your fellow group members than with your advisor. Therefore, you need to make sure that you can get along with both your advisor as well as your future colleagues. A miserable working environment is not worth the trouble, if another viable option is available. 

Also, make sure that the project you want to work on interests you; it'll drive you to accomplish more, and you'll be better motivated to make it your own (which is what you need to do to succeed as a graduate student).