Flywheel is a good question and so it bellhousing and motor mounts. It just comes down to a question of if the shop has everything needed for a Hemi or not. Most shops are not going to have the ability to run any engine. The Hemi has unique front motor mounts so if they haven't run one before they might need to build some brackets. If your Hemi has an 8 bolt crank then you'll need to double check to see if they are set up for that. Most shops are going to have the Mopar 6 bolt setup but they might not have an 8 bolt adapter.

You'll also want to ask about the water pump. Are you going to use a belt driven water pump or do you have electric? They will want you to remove the thermostat if you have one. I had one shop that required an input shaft bushing in the crank so their driveshaft would fit properly.