People, you will be communicating with, want to know, who is in charge of making decisions.
They don't have time to wait while you will be deciding who, why him, how much, where. They need answers.
So be straightforward, if you are in charge of making technical decisions and, as you wrote, have knowledge and experience, then name yourself as CTO. Who is in charge of marketing - CMO, if third person is making last decision, call him CEO.
When you have money to hire people on these positions, I think you can name yourself just a co-founder, who is able to pay ridiculously big money for specialists. If you want to stay with "cool" naming, become a President of Marketing/Technology/simple Big President.
If you want local variants, find them, as example, general director, marketing director, technical director.
Seniors/managers are hired specialists, who can be outsorced. Directors are making decisions.
Everybody understands that where are CEO's,CMO's,CTO's there is the board of directors, but today, with all that startup hype, people are used to meet with 22 years old CTO's of "three man startup".