To answer your question it depends on what type of mortgage you qualify for and how much you would like to put down. If you qualified for a conventional loan and wanted to put down at least 20% of the apparaised value of the home, then go that route.
If you wanted to put down less, then go for an FHA loan that will require a minimum 3.50% down plus closing costs. But remember, you must qualify for either loan and it will depend on what the lender comes back with on an appraisal. If the home appraises low and you basically have zero equity, that and your down payment will determine the type of loan you may qualify for.
Talk to a lender if you are working with one, if you are not working with one, let me know and I will give you a few people you can call and talk your sutuation over with.
I hope this helps to get you started, but more information will be needed to fully help you.