I guess I just don't get how they work. DH has a lot of seminary debt (I think it's between $70,000 and $100,000-- pretty much he took out student loans on 4 years of graduate school). I think IBR would be a good way to go, but I'm not good at thinking financially. Especially if we're going to have IRS payments, we've got to do everything we can to get the loans down.
Here's a link with a FAQ on the IBR for federal loans: http://studentaid.ed.gov/students/at...3109_FINAL.pdf
If the church he works for is a 501(c)3 then he may qualify for the Public Service Loan Forgiveness Program: http://studentaid.ed.gov/students/at...%2012%2010.pdf
IBR is going to be less expensive than any other repayment option because it is calculated based on your family's AGI and the difference between that and 150% of the federal poverty level for your family's size. It isn't based on the sum of your loans, which most of the other repayment options are. You do have to qualify for IBR as having a partial financial hardship (described in the IBR FAQ).
If you end up owing the IRS, I think I've heard Dave suggest putting student loans on hardship deferral, moving the IRS to the top of the snowball list, and paying them off ASAP.