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.

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!