Mike,
Your best bet if you can is to shoot me a phone call at the shop and I can go over some options. I will address some points briefly though.
There are several cams out there that can get your goal, but the unique part about a few is their driving characteristics. Most LS3 cam only cars making 470+ whp do not drive all the smooth per say, due to the overlap and aggressive cam lobe profile necessary to generate the power goals. Now there are a few we have worked with that we would recommend. Oddly enough I believe one member above mentioned the LG cam, which is one I may suggest from a shelf grind a vendor offers. That cam drives fairly well so long as you do not try to put the car in sixth gear going 65. There are a few other cams additionally that we may recommend, MTI makes one that works well, we have an options, Livernois has an option, Texas Speed ect. But again not all are created equally when we talk about drive-ability, and unfortunately some manners will just have to be sacrificed to a certain extent.
As for the parts you should change out - You should get a billet timing set if you are able to, valve springs and retainers (dual springs will be a must for this aggressive of a cam) , chrome-moly push rods (length around 7.425"), gaskets and such are also going to be necessary. Your stock rocker arms are fine, the only thing to consider is a triunion upgrade from Comp or Harland Sharp.
Good luck let me know if I can help.
Regards