You're mixing apples, oranges, and pears.
How do you get a good deal on an owner-financed home? Look for sellers willing to do owner financing. For a particularly good deal, look for properties that need some fix-up--where the seller pretty much just wants to get rid of the property for whatever he can get.
As for flipping it--flipping means buying, doing some quick fix-ups, and selling. If you're interested in flipping, don't restrict yourself to owner-financed homes. You're already getting a "favor" from the seller with the owner financing. To find a flip, look not only on the MLS but also at other sources: Wholesalers, for instance. Or make offers on properties that aren't currently listed. If you want to flip, you have to know your numbers--making sure you have enough room to buy, repair and improve, and then sell.
As for renting out a property--that's "buy and hold," not flipping. In this case, your only concern is that the amount you're paying for the mortgage (whether or not it's owner-financed) is substantially less than the amount you're collecting for rent. Again, you have to work the numbers. Some areas of the country are a lot easier to do that in than others. I don't know about San Antonio.
Hope that helps.