Consider buying with 1% to 3% down. -- Illinois has a great 1% Down loan program and you only need 640 credit and an income above $40,000/year.
(The homes are not usually in horrible condition. Renters don't pay a surcharge. They may or may not pay more than a straight renter would; typically, a portion of the rent is credited to the purchase price. The seller makes most of his/her money if the tenant-buyer exercises the option, so the seller--95% of the time--would like to see the purchase go through. I just had to respond to those erroneous statements.)
Here's a link to a blog I wrote on how to find rent-to-own properties. The big point here is that while some may be listed on the MLS, most won't be. Your Realtor often can help you identify some. And there are things you can do yourself to find them. Don't be discouraged if an agent tells you that there aren't many listed in the MLS. That's accurate information, but totally irrelevant to your search for a rent-to-own.
Here's a link to a blog I wrote on how to find rent-to-own properties: http://bit.ly/findaleaseoption
Hope that helps.