If your pally's going to be your main, you could try something like this:

#showtooltip Righteous Defense
/cast [target=mouseover,help,nodead][help,nodead][target=targettarget,help,nodead]Righteous Defense


I use it all the time on mine. It's from wowwiki, pally marcos section. There's also another one for using focus (i.e. set your healer as focus)