The fastest and easiest way to input family/funeral info with the least amount of errors is to have the family either participate (Planning Center) OR watch a Funeral Director type the info into a computer during arrangments.
I suggest a 'Passare Entry Form for Arrangements' that goes beyond that Planning Center. It would be designed specifically for gathering all the data in one meeting rather than getting 'some' information from the Planning Center and 'some' information from arrangements and combining the two.
This Entry Form would be elegant in it's design and easy to figure out on it's first use. If they use Planning Center ahead of time, all the info would already be in the entry fields when they arrive.