Do I take this apartment to get away from my abusive brother?!

If you feel your brother's abuse is an imminent threat, better to get out now; risking your physical safety won't do those cats any favors. But it doesn't seem like a great long-term solution to just move down the street and expect to be suddenly free of your brother's harmful presence in your life. You need real distance from him, so maybe it's worth a few extra weeks of searching to avoid having to go through your relocation all over again when he starts harassing you in your new place. I can't fault you for wanting to provide helpless pets a better home, but you need to think long and hard about how you're going to accomplish that. Just running off with them is going to make your brother go ballistic, and he's going to have a justifiable reason to track you down and confront you for which you might not have a rightful remedy. Not that he'd be condoned for any violent action to get his cats back, but you're provoking him and that can't possibly end well. I don't have a solution for you, but you need a clearly thought out approach to the possible consequences of this well intentioned act. Maybe contact the ASPCA or a local shelter and ask for some advice--perhaps they've dealt with similar situations and can give you a better idea of what measures you can take to rightfully protect at-risk animals. I'm sure they can't offer you legal advice, but they might be able to guide you in taking your next appropriate step.

I think you should move into the apartment and take the cats with you. If he won't let you take them you should get in touch with your local animal welfare service and get them involved.

I agree with ami-ami