The Pitbull looks nice and all, but I feel like it might get a bit crowded after a while, especially if you have a large group in Grid. It could easily overwhelm your screen. I'd suggest maybe finding another way to display the information you need, like a HUD addon.
I personally use IceHUD, and I have the casting bar showing up there, as well as my health and mana, but you can also add target and target-of-target information. Won't be as shiny, but won't nearly be as cluttered. Also, I can't tell if you have one, but a scrolling text addon is always nice. This is roughly how my UI looks, for an example of how I like it:
This was before I started using IceHUD.
This is my UI with IceHUD with all the bells and whistles, including cooldown tracking and JOTP uptime. I don't use Target or Target of Target via IceHUD, although it is possible, and there are certainly different skins if you don't like the faded look of mine.
Edit: Someone else just suggested ArcHUD, and IceHUD has a look that imitates it, but unless it's been updated recently sometimes ArcHUD can slow down your system dramatically. That's what prompted me to try IceHUD in the first place. IceHUD is extremely, obscenely configurable.