I would not recommend sending personal checks to BCIS at all. I agree with Neha123. Send either Money orders or Cashier checks. If something happens, you can keep track of it. Keep the copy with you. As far as the address is concerned, check the website before you send the application. Now there is a transition in the name change. So, they my accept any name ( BCIS, USCIS). So, it depends on when you are applying. You dont want to take any chance!
Kamal