Rent-to-Own

You absolutely must have your own lawyer involved before you sign anything on a rent-to-own. Yes, you could probably use a personal loan for a down payment, but before you do that, you need all sorts of protection.  You need to know -- is the landlord current in his property taxes?  His mortgage payments?  Are there other liens on the property? 
Then there are the details of your contract:  how much credit will you receive toward the purchase price?  Who pays property taxes along the way?  Could you sell your contract to another buyer if you decided not to complete the plan after you'd invested real money in it? 
Be prepared to pay for a real estate lawyer's assistance, right from the start, or you're likely to end up in trouble.