maidana by ko. i don't know about valero's chin. he's been hurt by mosquera before and has not been tested by a known power puncher. maidana on the other hand has proven he can recuperate very well.
If reports Valero beat the crap out of DLH in sparring for the Pac fight are true, I would go for him.
Valero reportedly beat Morales in his preparation for Manny Pacquiao (first fight) And same goes for the black eye DLH sported, Valero even told him Pacquiao would whoop his arse and that he should "MAN UP AND DO HIS ROADWORK"