I would recommend scepter/focus, because you have 4 Blast Finishers on your weapon skills. Depending on your traits you can get up to 6 Blast Finishers. If you are playing with a ranger you can burst-heal 15k (if one blastfinisher heals 2,5k) and furthermore you can heal your group about 2,5k every 5 seconds while the water field is lieing (Dragon’s Tooth). You can also stack might (18 stacks) if you use a fire field instead of a water field.