I just got a new JVC cd HU, and a new set of speakers for the front, my question is can the rear stock speakers handle 19w? Also, are the front and rear oem speakers the same (in size and power)? I don't really want to spend more money on a new set of rear speakers...

 

The rear speakers will handle the head just fine. I've had mine running off a pioneer for a year without a prob. If you got decent front speakers, you can just leave the stock ones as rear-fill.