Most of the MBA schools(the good ones) do require a GMAT or GRE score. However here a few ones which do not require GMAT.
- IE School of Business - They have their own exam
- Rotman School of Management – University of Toronto - Depends on profile
- Schulich School of Business – York University - But requires you fulfil some criteria
Per se the job, the experience of just knowing SAP will not help you directly, but what will help you is what you did in those 6 years. SAP was just a tool, but how much did you impact your work place with your knowledge of it and how you took it forward. For example, with SAP experience this will become a talking point that you have Supply Chain experience and you want to add Business knowlege to push forward your career.
All MBA programs have Operations & Supply Chain as the key major in their curriculum.
Here a few links
1) Supply Chain Schools
2) MBA without GMAT