Super Prot Pally mod. Has RF cast button, Argent Defender counter along with Avoidance stats. Right click the header to show/hide all of the frames. Left click the Argent Defender info to reset the data.
/tankadin will give you the options.
Thanks to James from http://www.maintankadin.failsafedesign.com for the AD Tracker code.
Look up CrushTable if you want a window with just avoidance stats.