If you're already getting an MHS, and want to go to medical school, I don't really see the benefit in getting another Masters degree in a public health related discipline. You should look for some work experience now before applying to medical school. Apply for some research fellowships (abroad or domestic), try and get a job, do some research, get some more clinical experience for your med school apps, etc. Even if you get a full ride to do another degree, I don't think another masters degree would help your med school app as much.
It also depends on what you mean by scholarship. A school that makes you pay $15,000 per year for your MPH will be better than a school that gives you $25,000 scholarship but has a $50,000 yearly tuition. If you're really set on getting another degree, I would definitely consider applying to state schools which will be cheaper (whether you get a scholarship or not), if all you care about is the degree. Each school will have full-ride scholarships, but these are traditionally given to people who are very competitive, have had some years of work experience and whom the school really wants to attend their school (if you're not at that level, you may not get those full scholarships).
So like I said, focus on getting work experience, applying for some research fellowships, or even do a Fulbright program abroad. Another Masters degree is not the way to go, IMO.