Also Is there an addon to alter the default Hover over tooltip?

I used Shadowed Unit frames; I have a player and target bar in the centre of screen - you can track buffs and debuffs below the bars.

For the latter - tiptac - lets you change and reposition the tooltip notice, and add things like spec etc for players.

I am sure you can set PowerAuras up for that. The closest I think of is how I set up my paladin, to show if my enemy target is under 20% health (for Hammer). On Power Auras, you can set any style you like (text, flashing horde symbol, etc :), wherever you like, with your preferred opacity.

@darky: the other issue - tooltip
Get TipTac, its great and fully configurable tooltip addon.

Satrina Buff Frames. I use it to show only my diseases on the target and it works great! I also use it to show debuffs on me (and the debuff count, if any) to help with tank switching.

Ok thanks guys I just went the route of using quartz to make the bars nice and easy for me to see, right next to my portrait too. I have tried using power auras before but in the end I found its too much hassle for me and other addons are usually there to fill it's place with a lot less hassle.