Main priority is gaming. I can't decide if superior image quality or higher resolution would make gaming more enjoyable. I'm also worried that, when dealing with 16:9 media, if the black bars and lack of screen usage is going to annoy me.
You should not let black bars annoy you since there are many different aspect ratios which movies are filmed at. The popular ones are 2.35:1 and 2.4:1, but there are many others. Whether you buy a 16:9 or 16:10 monitor you will get black bars with many movies.
As for the LCD panel technology, IPS is better than TN when it comes to color accuracy (once calibrated) and viewing angles. However, the Dell 2209WA is 1680 x 1050 which means watching a 1080p movie results in the video being shrunk down to fit the screen. This is known as interpolation and will cause a small decrease in video quality. Most people will not be able to tell the difference watching a 1080p movie on a 1680 x 1050 monitor vs. 1920 x 1200 or 1920 x 1080 monitor.
As far as gaming, the lower resolution of the Dell 2209WA will be less taxing than the 1080p Dell ST2310 monitor. Of course on the ST2310 you can always set the game resolution to 1600 x 900 and then stretch it across the entire screen to improve performance with a slight hit to image quality. After all, this is the technique used by the PS3 and Xbox 360; the render games at 1366 x 768 (or lower sometimes), then stretch it to fit a 1080p HDTV.
I'm not really worried about taxation of my video card, though. Mostly worried about FoV and which of these monitors would make my games overall more enjoyable. I didn't know if the IPS' improved image quality or the TN's higher resolution would work best for that.
That being said, the IPS panel monitor is $135 more expensive (after tax), and I'm already $200 over budget with this new rig. I think I'll go with the TN for now, unless Dell pulls out some sort of sale before I order my parts.
If you use VLC media player you can crop the video to fit your screen i have a 16:10 and alot of videos are 16:9 i use it to crop the video and then it fills whole screen with littl loss in the wide angle but no more annoying black bars.
If you did that with a 2.35:1 thru 255:1 aspect ratio movies (it's called "cinemascope" which also "panovision" and "cinerama"), then you will be losing a lot actual movie "real estate". Such cropping on those aspect ratio could result in the actual "action" taking place off the screen.
As far as I know, the widest widescreen format is called Ultra Panovision who's aspect ratio is 2.76:1 which I think was used between mid 1950's - mid 1960's. Ben Hur is an example of an Ultra Panovision movie. Haven't seen the DVD or Blu-Ray so I don't know if the movie is actually in 2.76:1 aspect ratio or has been cropped down to a "not so wide" widescreen format.