It really depends on what you want to get out of the degree. I'm in a different scenario and had to turn down CMU with some aid, because it didn't actually align with my intended career path.
The Harris full ride definitely looks like the way to go, and I'd look into SIPA only if you can back yourself completely to get second year scholarships and get your dream job after you graduate. If it can help, I'd suggest you join the linkedin alumni group of both Harris and SIPA and check out what people do after they graduate. And it includes both recent and old alumni, average alumni, top alumni, the whole bunch. I just think it could give you an additional perspective and justify your choices.