The fact that you have little equity is a GOOD thing as far as a CH 7 bankruptcy is concerned. There are exemptions in every state that allows you to keep certain property. In OK, homestead are 100% exempt to an unlimited amount. So no matter what your equity, your home would be safe.
Here are you OK exemptions. Anything not on that list or having a value above the exemption amount could be taken by the Trustee.
A reaffirmation agreement is a new promise to pay which you would have to sign. Reaffirmations are voluntary, but in some states if you want to keep the property, you have to reaffirm. All this does is give the lender a legal warm-fuzzy that you're going to continue to pay on your obligation and if you don't, they can foreclose. That's a rather simplified definition, but its the basic idea.