Best to source the heads before the cam, IMO. I'd run BBM/Survival/TFS for a 462ci combo like you're spec'ing as the larger displacement will like the better flowing heads.
Just as a ballpark, a hydraulic flat tappet in the 235* and .550" area would be about minimum to feed a 462 and would definitely be stout down low, especially in a relatively light mustang.
The TriYs would be ok for this combo