Mike, cam specs will depend upon what the intended use of your car is, how its set up, etc.
The physical limitations of the ZZ6 engine are that it has 9.6:1 (some say 9.7:1) static comp. ratio and the Fast Burn heads are limited to 0.525" (some say 0.530") valve lift. So you need to work within those parameters with cam choice.
As reference, when the Fast Burn heads were first developed, they were used on the limited production ZZ430 engine. These were GMPP crate engines that dyno'd at 430 HP. That's why they were called the ZZ430 and only 430 of them were built, each having a serial number of 1 through 430.
The ZZ430 was a ZZ3 / ZZ4 short block with Fastburn heads, the LT4 HOT cam, 1.6:1 rockers and an intake manifold produced by Edelbrock for GM. The intake was the same as Edelbrock's non-airgap Performer RPM cast with a GM part number. Carb was a Holley 750cfm vac. secondary and distributor was a recurved HEI. Headers were 1-3/4" primary matched to the 'D'-port exhaust with 3" collectors.
HOT cam specs......
https://www.gmperformancemotor.com/parts/24502586.html
LT4 Hot Cam - PN24502586
Hydraulic roller
Duration @ .050" Lift( Deg): Intake: 218 / Exhaust: 228
Maximum Lift (in) W/ 1.5 Rocker: Intake: .492" / Exhaust: .492"
Maximum Lift (in) W/ 1.6 Rocker: Intake: .525" / Exhaust: .525"
Lobe Separation Angle (deg): 112
Technical Notes: Service only; for all V-8 engines with roller cams.
As reference, the earlier 350 HO GM crate engine (AKA ZZZ engine) cam specs......
ZZZ Cam - PN10134334
Hydraulic roller
Duration @ .050" Lift( Deg): Intake: 235 / Exhaust: 235
Maximum Lift (in) W/ 1.5 Rocker: Intake: .480" / Exhaust: .480"
Maximum Lift (in) W/ 1.6 Rocker: Intake: .512" / Exhaust: .512"
Lobe Separation Angle (deg): 114
Technical Notes: Service only; for all V-8 engines with roller cams.
Best thing I can suggest is to give Mike Jones a holler regarding cam specs for your engine.
These ZZ6 engines are same spec as the GMPP '604' sealed circle track engines only without the circle track oil pan and valve covers / breathers.
So cam grinders like Mike Jones are familiar with them and should be able to help you.
Hope this helps,
Harry