I use Wills a lot. The way I handle them is to use the standard Will and Probate facts on the record for the testator. All the individuals named in the Will are recorded as Witnesses in the Will fact. Sometimes it is necessary to add an additional category of Witness to meet the circumstances, e.g. Named Person is a good catch all. If you then look at the record for the individuals named you will see that the information flows through from the Testator's record.
With a lot of trial and error I also managed to write a source template which has fields for name, place, date written, date proved, archive, archive reference etc. In the source text I record an abstract of the Will. The source and abstract also flow through to the individual records. I create one source per Will.
This method works for me but I'm sure there are many other good methods of dealing with Wills.
Hope this helps.