Originally Posted by CSoars 
But then he'd require lenses with aperture rings!
He stated that he had been using film until fairly recently, so I don't think old(ish) lenses would be problem...
anyway, tough choice. With K100 you just take bunch of Lithiums and they'll last...
On the other hand, I switched from K100 to K10 just like month ago and trust you'd love K10. It's a cracking camera and these days you can get it for fabulous money.
As I said, tough choice... good luck