The way I've seen this done and how I've structured this for my own startup: your contributed time is your equity (vested over four years), and your contributed capital goes on a convertible note. Any cofounder who wants to level up and contribute capital can have the same deal. Keeps it very clean and fair. If one of you leaves behind unvested shares, your capital doesn't vaporize.
As others have pointed out, what concerns me is the 50% after you've de-risked the startup, and the non-voting shares. Maybe this cofounder is worth the 50%, but why negotiate against yourself on the non-voting shares? Two classes of shares is just more billable hours for your lawyers, in addition to being unfair to you. You're already offering him a generous amount of equity in good faith.
Are you wanting to structure the deal this way because you want your cofounder to be CEO? The CEO doesn't need 50+% (and rarely has it, except maybe for a fleeting moment at seed stage) to effectively manage a company.