Single-stat gear (e.g., the Randomstat Green of Healing or of Intellect piece) is always less desirable than balanced stat items (e.g., of the Eagle, of the Bear, of the Gorilla). You want to aim for the balanced stat items, since they will enable you to both instance heal and solo in the same gear.
One worthwhile exception is the
Truesilver Healing Ring which can be equipped at lvl 43. I would always swap that in and out for the lesser of my other rings whenever I'd heal for a group.
On a server with a normal economy, you should be able to get the right stats on decent lvl 40-55 plate pieces for a reasonable price. Don't be afraid to spend a little coin at the AH to get quality gear upgrades once in a while.
Edited, Mar 26th 2008 4:08pm by HoyadinFTW