Intriguing idea - perhaps getting rid of the power gage, and enlarging the health gage to the same size as on the Player Info window, and putting the percentages on top... something like:
Health % / Power %
And color-code the percents to make them readable at a glance. Until I can work up something like that, "mousing over" will give a tooltip with the exact percentage and numbers - I use that feature on my 2-box wizzies while he's on Auto-Follow.
I'll see what I can whip up, rawr (no promises on speed though - might turn out to be trickier than I think)