An MPL can not be self sponsored. You can only do an MPL with an airline, and then your license is specifically for that airline on that aircraft until such a time as you meet the requirements to unfreeze at which time it does become an ATPL. But until then, you are restricted to that airline and that aircraft (as far as I know, you can't take the type rating to another airline but they are so new I am not sure this has ever been tested)
In either case the ground school (14 ATPL subjects) are the same.