The reading of the Gospel is a dramatic moment in the Roman Rite. The other readings are done by lay people usually but the Gospel requires the Celebrant or a Deacon. Singing it can make a great contribution to this part of the Mass. But hardly any celebrant has been trained to point the words to the Gospel tones, and most certainly lack experience in this skill.
For this reason, I strongly recommend that you buy your priests this book: The Book of Sung Gospels from CanticaNova. Mine came in on Friday and I'm very impressed. It covers all the major feasts in the new calendar, 42 in total. The printing is large. The music is easy to navigate, and, since it only involves three notes, it is not difficult from a musical standpoint. The difficulty is knowing where and how to change notes. This book takes care of the entire problem.
It is a paperback, saddled-stitch book, and one that every priest will really appreciate. This precisely the sort of book that they don't tend to buy for themselves, for whatever reason. But if a layperson buys it and gives it as a gift, they will pay attention. Oh, and it also includes all the apparatus that might be important to some people (approved by the Bishops Committee on the Liturgy, etc.)
It's $24 here.