The question is a little vague but I'll my best.
1. An accountant or maybe book manager (depending on the business)
2. A commercial attorney/lawyer.
3. Someone in charge of operations.
You might not have to have these people as co-founders and it might be enough to use them as service providers at specific stages. Again: it really depends (1) what the exact business is, (2) what your background is and (3) what you're looking for (someone to take the journey with you or just someone to do what you need and that's it).