The specs on a custom grind cam will be (should be) tailored to YOUR COMBO (which consists of engine size, heads, desired max rpm, type of trans, rear gearing, how much boost you want to run, type of intake, compression ratio, etc etc etc).
For example, my custom centri cam was 610/575 235/260@050
, 115+6LSA. My custom turbo cam is slightly bigger than that. I would say the specs but I don't know if CPR wants them out... I love the sound of a big cam and have no issues with a little bucking at low rpm. The centri cam bucked just a small bit and idled at 900rpm. I knew this and gave it a little extra gas when idling through a parking lot under power. I will do the same for the turbo cam.
Who is best is subjective. Common names are Brian Tooley, Pat Guerra, Ed Curtis, Martin at Tick performance. There are many other too.
Pyro, ask yourself how much power do you want at the wheels? The stock LS3 cam will make over 600rwhp. When it comes time to forge the engine, get a custom cam at that time. Save the money now for forging later. Don't waste money on a cam right now if you know you are changing your combo later.
A cam should be the last piece of the puzzle you figure out as it ties the build together.
I am sure the night fury cam will work. It works extremely well for centri applications. Think of this though - most cams such as the night fury, JRE, G6X3 cams are all around $400. A custom cam is also $400. It just takes a couple more days to get it shipped to you because it has to be ground. Talk to your builder and if a cam that is already established has the specs you need, go for it. Otherwise, custom.