There can be risks with a land contract; google that term to read about some of them. In any event, expect to make a good-sized down payment and have a credit check run and provide proof of income. Good luck!
You need to know what your qualifying FICO score is. Many lenders accept 620 and a 640 is even better. You're either there or perhaps not far away. You also need (2) years of steady employment. Your debts (including a 1.50% factor for any deferred student loans) needs to be compared to your income to determine how much home you will qualify for. Until your wife has (2) years of tax returns for her corporation, there is no consideration for any potential income.
All questions that can be answered if you meet with a mortgage professional. If you don't qualify right now, they can advise you what your short comings are, what actions need to be taken to overcome them and how soon you will be eligible to buy plus how much you will qualify for.
All the Best,