My favorite way at this point is doing a video feed of the healers bars with mouse transfer. I used to use repeater regions but I like this a lot better. CtrlShiftAlt G is the default way to pull up the feed configurations. Make the feed on your healer first (and name it something other than just hisher name).

One hint: if you're using a standard 1 big, 4 small setup, make the grid/party frames on the healer twice the size you want to see them and then feed it into a box half the size. This helps with the "I hate how my bars are all blurry" problem that you get if you are running your healer at 1/4 the size and you try to blow up her bars to full size on a feed.