I would stay away from JBL, that is my opinion.
In my experience, the old saying "you get what you pay for" applies to car audio.
The kickers you chose for your subs are a great choice, I've been more than happy with kicker subs I've had in the past.
As far as speakers go, this is the hardest choice. I have yet to hear a 6x9 speaker that sounds great in a stock location. I would Install a 6.5" round speaker component system in the 6x9 location. The 6.5" component system in the front doors is a good idea, if you can fit them. For speaker brand I would stay with a high end Infinity or Polk. Kenwood makes awesome electronics, but I've been disappointed by their speakers.
I'd suggest purchasing a kenwood amp however.
I've beat the snot out of Kenwood amps in the past, and it has never failed.