I have friends that are great coders, but I know they probably wouldn't be a good co-founder. I also have some friends that would make great co-founders.
It sounds to me like your friend would be a better employee. Founders of a company should be sacrificing and busting-ass every waking moment.
Could you ask him to fly/temporarily move to your country?
I have asked him to move temporarily, after months of "nagging him", he has agreed to come for a month at a time.
But I feel like it's kinda self-defeating, I should not have to nag him to get him to do this.
In your agreement, you both should have a long period of founder vesting. Then, should you part ways, you can give your co-founder his share of equity multiplied by whatever fraction of the four years he worked.
Getting the paperwork right doesn't end with the shareholder agreements - you also need to make sure all the intellectual property is assigned to the company.
Actually, what you really need to do is sit down with a lawyer that knows what they're doing.
So that is a contract if you will.