Proving income for wife's green card OR what can I count as income? (student loans)?

As long as you can establish taht you are going to receive that income every month there is no reason it would not be included in your application as legitimate income. I am not sure though if you need to apply for a green card, I'm thinking there might be some other visa you want...it seems like it's harder because if you weren't a US citizen you'd be a shoo in for a F-1 visa and she could come with you on that no problem...