I think minimum income is better. Minimum income doesn't have to be something that allows you to live comfortably. It can just be something that ensures you can have basic shelter, minimum required food, clothing, healthcare, etc. Basically, people should be living in poverty but without starving.
This way, there is still the motivation to work because few would choose to live in poverty if they can help it, but at the same time you look after those that are out of work for some reason, until they find work.
With minimum wage, you have no power to progress financially if you're in a job paying minimum wage and you can't get another higher paying job. And what happens if you lose that job? You have no income! So minimum wage can be like slavery. But minimum income is a basic protection for all that will give employees the freedom change employment. It better equalizes the power play between employee and employer so that neither has too much undue power over the other.
In fact, I don't think it should be a case of either or. It should be a case of both! You have minimum income to allow the unemployed to survive uncomfortably without starving and without taking away the motivation to find employment. And in addition you stipulate a minimum wage to ensure employees are treated fairly. So basically you would have a minimum income for everyone and working people get at least a minimum wage added to that. No working person would be living in true poverty. Only the unemployed would be poor but at least they won't starve.
