22" Widescreen LCD for Gaming

I am looking for a monitor for my new system. I want to get the most out of my Q9650 and 1gig Radeon 4870 without spending more than 300 bucks if possible. I have heard people comin down pretty hard on TN Panel setups because I guess they have crappier color? How do I know which monitors have TN Panels and what kind should I be looking for instead? Also I have heard that HD rated models are worse for performance, but by how much? What does HD mean exactly does that mean it runs at 720p or better? Where's the cutoff? Ok enough questions for now. Ha. If anyone can help with any of this it would be tremendously appreciated. Ty.