I would advise against incorporating a company until the first sale is made. You want to delay this as much as possible. When you do incorporate, setup reverse

I would advise against incorporating a company until the first sale is made. You want to delay this as much as possible. When you do incorporate, setup reverse vesting for him so you can easily get his equity back in the case you have to fire him. Vest his equity over 4 years with a one-year cliff. This way you have a full year to evaluate if you want him as co-founder/salesperson. If he is not happy to be under this performance-based scheme then that's a huge red flag. After all, you have already proved you can hold your side of the bargain but he has not. If you are already incorporated then you will have to setup a stock option pool with similar terms. In terms of fairness of compensation, this depends on the competitive landscape. You should probably try to source a few more potential salespeople to get a feeling of what that landscape looks like.