Maybe I'm missing something. But either you're addicted to education or you're not clear on your goals.
First of all, you should either pursue an accouting qualitification (ACA/CIMA/etc) or an MBA, but there's very little reason to pursue both. An accounting qualification will likely lead you down the finance side of the business; an MBA is a little more general.
Second, you should ask yourself whether either of them have value in an implementation practice? If you intend to spend your career in an implemenation practice, you're likely to end up either as a functional specialist, a technical specialist, or a large project / programme manager. These each have their own educational requirements, but think along the lines of PRINCE2, not MBA!
Finally, you need to consider the organisation you're proposing. I worked at KPMG long ago, and as a rule they trained their accountants on the audit side of the business, not in IRM. So if you're looking for KPMG to sponsor your ACA (and they'll need to, because you can't get your ACA without relevant work experience), you might want to address this up-front and make sure you're entering the right part of the business.
I wish you good luck, but think you need to understand a little more about the dynamics of an IT consultancy and a little less focus on academia. While a good degree is vital to get in the door, you'll find that on-the-job experience is much more important moving forward.