You get a home - They get improvements to the home - If you do not make payments they will have a much improved home - That will be your investment to prove that your commitment to the deal.
A lawyer can write a contract that will spell out the particulars and protect both the buyer and the seller. We used Hendrix & Hendrix in Hayesville and they were very reasonable in their price - also they can think out of the box, since this will be a bit different than a normal contract. It may take a few attempts but I bet you can find someone who would appreciate yout good references. Keep in mind that you may find a lawyer to actually represent you and write the letter for you to show the intent of good faith as a buyer. It all goes back to the old timey way of bartering goods for goods. There are alot of good honest folks that need an opportunity - This can be an opportunity that helps both parties. Good Luck !
There are sellers out there who are willing to do seller financing. However, they typically are going to ask for a credit report AND at least a 20% down payment. If your price limit is $60,000 then you are going to need a down payment of at least $12,000 with another $1500 - $2000 for closing costs (attorney fees, title insurance, pro-rations of taxes, homeowners insurance, etc).
I would suggest speaking with a lender who offers loan programs such as USDA which requires a lower credit score and will do 100% financing. I will be more than happy to recommend a couple of lenders.
My other suggestion would be to start working on raising your credit score and saving for a down payment. Make sure you pay your bills on time or even before they are due; pay down balances on credit cards (don't close accounts without speaking with a lender as closing accounts isn't necessarily always recommended); create a savings account and at to it regularly. You should have an amount in savings that is equal to 6 months of your monthly bills. In other words if your monthly bills are $1500, then you should have at least $9000 in the bank PLUS the $$ you will need for a down payment.
To make sure you can really afford the home purchase, you should also be setting aside the amount that owning and maintaining a home exceeds your current rent. If you are paying $500/month in rent and your mortgage payment, taxes, insurance, and planned maintenance for the home will be $900/month then you should be setting aside an extra $400/month. If you can afford to this, then you can be confident you will be able to support your housing obligation.
Fixing your credit is the best place to start. It may not be the answer you're looking for but it truly is the best plan.