There are many degrees out there. An MBA may not be exactly the right degree for you. Don't cross off a school just because it doesn't offer an MBA, if it offers a masters of science in business administration or finance or other business related subject. Know you have options other than the MBA. BUT, if you intend to continue to the PhD, make sure you know the school's requirements for this degree.
If your ultimate PhD school requires a master's of science in some business related field, such as finance or economics, make sure you cover that base. Some schools feel that the MBA is more practical and not up to the rigors of an academic degree necessary to prepare for the PhD. You don't want to spend all that time and effort earning one degree only to find that it won't get you where you want to go.