GSOC Proposal Doubts

I am planning to work on the django org problem statements in gsoc which involves working on the type stubs so I am planning to write a proposal, but right now debating on which module/function group or groups I should target.
I was thinking the auth and session models (contrib) might be a good starting point and then move to django.db.models, what do you folks think. What would be an ideal amount of modules/groups that can be covered under this problem statement for gsoc.

Also once I do start writing the proposal, I am assuming I can post that on this forum for refinement and community feedback should that include only methodology/approach or the entirety of the proposal i.e defining the problem statement, approach, timeline, experience etc.