Getting caps on front teeth, doing whitening now, have questions?

I'm getting caps done on my two top middle teeth (called 1 and 2 i think). The dentist gave me the molds and syringes for whitening for the rest of the teeth, they're very discoloured. I have some questions. I need to know for when to make the appointment to get the caps. Once I finish the whitening, do i need to wait a week or something before getting the temporaries so that the colour has time to "settle"? Do the whitened teeth need a few days so that they can come into the colour they'll be. Or if i finish the whitening on a friday, can i just go straight in on saturday or will the temporaries then be brighter then the rest of the teeth because a week from then the rest will darken. ok, i hope that made sense. question two. When i asked my dentist whether i could do the laser whitening she said that the trays are better. my teeth are pretty "yellow" and even the dentist said that they wont go white but they'll just be "brighter". Once i finish the trays, can i just go in and do the laser whitening so that i ensure i have whitest colour possible before getting the crowns. will that damage my teeth if i follow the one whitening treatment after another? i just want to make sure the whitening is done as well as possible and i dont know if the trays will do that. The reason she said that the trays are better is that the results last longer, so if i get the laser done, will it soon go back to the colour that i would have with just the trays? i dont want my teeth to be a different colour from the crowns sometime down the line so i have concerns about that.
--------------------
I recommend that you wait at least a couple of days for the color to stabilize. I agree that I don't like laser whitening. It really only gets the surface white and doesn't last very long. The trays are much better, plus you can do those any time at home when you feel that you need more whitening. You are also more in control with the trays. As soon as your natural teeth are the same as the caps, you can stop. Laser is so fast that they may over whiten.
Source