You wouldn't be any more crazy than those of us who have done exactly that!

When I found out my friend and I didn't have compatible blood types, I decided to donate to a stranger. You could also join a paired exchange program where you donate your kidney to someone else and their "donor" gives to your recipient. They might be able to find another prospective donor that would work for your recipient and wouldn't have the antibody problems.
I had done so much research and was positive I wanted to donate so I talked to my family when I was considering donating to a stranger versus my friend. They thought I was a bit crazy, but they supported me. It was a wonderful experience and went well for both me and my recipient. I'm so glad I was able to help him and now my friend is looking forward to a transplant in the near future.
I'd say do your research and see what your options are. Talk to the hospital and see if they'd enter you two into a paired exchange. If not, you can always look here on LDO at the message board where people post if they need a kidney or are willing to donate one. That is where I found my recipient (I am AB+ so I looked for people who were AB and in need of a kidney). Best wishes for both you and your recipient.