No need to change lifters in a 6.1 hemi for a cam swap:
-Roller cams DO NOT require lifter changes. Unlike the old school flat tappet cams that do require lifter changes with cam swaps.
-5.7 motors with MDS DO require a lifter change for the MDS cylinders (there are exceptions, but this is a good general rule to follow)
Usually a spring swap is recommended. Which can be done without removing the head. As I'm sure you know, removing the heads costs about $100 in gaskets and TTY bolts, which is why most try to avoid it.