>Take the nucleus from one of your cells
>Insert it into a fertilized egg cell
>Implant said egg cell into a woman and let her be pregnant with it (essentially cloning yourself like what was done with Dolly the sheep)
>When the fetus develops, suppress the Hox-genes that cause a head segment to form
>Eventually a headless clone of you is birthed
>Keep it alive through IV drip with nutrients
>Add whatever hormones it needs to grow properly

And voilà, you have a patient matched organ donor with young and fresh organs that you can harvest when you need to. There's also no ethical issues since the clone never had a brain and therefore isn't sentient.

Maybe you could even transplant your onto the clone when you become old?
Thoughts?