Does anyone know of any scholarships or grants for pursuing an MBA?

Sure. You can ask at the schools you are interested in. One really great program that I personally know of is at the Johnson School of Management at Cornell University (recently rated number 11 among MBA programs in the country by US News) - if you are a US citizen they have a leadership program you can apply for that pays full tuition and gives a stipend. See:

Johnson School at Cornell University - Park Leadership Fellows Program