Well, the first obvious step is a very good GMAT. with a super high GMAT (lets assume for arguments sake 720+) almost every school can become reasonable to apply to even with a 2.2 (the big three will be tough though).
And the second step (this is where we come in
) is to write unbelievably, beautiful, intelligent, motivating, driven stories in your application.
Whether you get your CPA or not will be a bit less relevant to your MBA than the GMAT, so I would suggest focusing your energies on the GMAT first and your CPA, if you aren't in a rush, you can finish after you have completed all your application.