The Marauder is an excellent group support healer with its hangar bay and the Ensign Sci slot (yes that makes a hell of a difference).
After that you can play around with the different Bortasqu ships but the best option would have to be the Sci one (sorry the name escapes me) and it's just as good a healer, if not better than the Marauder. Overall though I would go with the Marauder if your purpose is to be the main healer for a group as the hangar can be fitted with shield repair drones or another hangar that effectively supports the group.
Finally the Vo'Quv is capable of providing group support and healing, but it is weaker at the healing role than the above ships, while being stronger at group support by virtue of the Cmdr Sci slot and the double hangars.
The other ships you listed are DPS ships and not viable as effective healers.