Before naming your remaining executive management, you might want to think about how the organization plans to grow:
Might there exist the need to bring on external members of the leadership team, down the road a little (this means you should leave some suitable titles sitting on the back burner, in anticipation)?
Does the mid-range business plan call for rapid employee growth, slow growth, minimal growth, large numbers? This will impact the nature of the developing hierarchy.
Will the operations be managed and nurtured on a more horizontal basis, or will the organization prosper under a more traditional “top-down” model?
While titles should mean less to people who are inward facing and intent on staying on board for a very long time, the more externally exposed your executive is, the more thoughtfully structured their title should be, as it communicates their standing in relation to the contact they are meeting (hierarchy), as well as their functional responsibilities, thereby suggesting what types of internal influence/oversight they may have. It also serves as part of the organizational brand positioning, in that it communicates the structure, personality, and internal relationship paradigm of your company.
Think as much about where you want this “right-hand person” to evolve as anything else:
Startups require their leadership to multitask, and step in to the breach wherever required. Sometimes they will function as a true executive leader, and sometimes the toilet will need unclogging. Some startups exhibit a degree of insecurity about bringing someone on who has a track record of leadership, for fear that the individual will not be willing to “roll up their sleeves”. Instead, the fledgling company avoids hiring proven executives, and places aggressive but inexperienced “up-and-comers”, hopeful that they will “grow in to the role”. I suggest it is easier to find an extraordinary executive who can answer the phones, than an intern who can effectively develop a budget, business plan, or marketing strategy. If you find someone willing to take a pay cut in return for a balance of equity participation, sometimes the risk will be exceeded by the reward.