Looking for input on how to fairly structure equity/ownership stakes in a potential deal.

Some background:
- Two parties involved in the deal
- Equal equity injections will be made by both parties
- Both parties will be on the loan and sign PGs
- One party will act as CEO and take a salary
- The other party will be involved but in more of a higher level/advisory role but still actively involved. Not day to day, however.

Questions:
1. What is the fairest way to determine equity ownership for each partner at this stage? Based on equity injection percentages?
2. Does a MIP make sense for the CEO to earn more equity over time per an agreed upon vesting schedule?
3. Other considerations?

All thoughts and inputs welcome. Thank you in advance!