for a 19"? 8800GS or 9600GT. You won't need much more than that. And with the list you are providing i take it you are going for a budget system.
If you go 8800GS stay away from the XFX, they have a different cooler that keeps the fan at 100%,which really leaves you with the eVGA, which is a great card. The 9600GT's are plentiful, some have nice coolers. I don't think you really need a 8800GT/GTS unless you want to spend the extra cash. What did you want to spend.
PS, what is the POWER-450W? is that the brand or who makes the PSU. just wondering.
a 9800 GX2!!! lol jks for a setup like that I go with Jay2tall, 9600 GT would be ur best bet or 8800 GT (The gs's ram might bring you down for certain games, my 9800 GX2 still staggers with Quake 4 everything maxed and 8x, i see the frames dipping to 20s sometimes...but it was running on a slightly improved doom 3 engine which was really poorly optimized compared to source)
and if you go for a psu get over 500, or 600 to play it safe for future upgrades or changes to the system.
Go 9600GT 512MB for 19" and additional get yourself a good PSU, say around 500W-600W. I agree with jay2tall and L1qu1d, just take precaution, if next time you wanna upgrade your system or add another hardware into your rigg. Then you dont have to upgrade your PSU as well.
Its at a price delta too that is pretty affordable for the quality you are getting - I highly recommend it, i'm very happy with it so far.
video card, i'm using SLI 8800 GT's from EVGA - but a lot of people recommend 8800 GTS 512 mb for a single card solution - i'm pretty happy with my configuration; i've used a single 8800 GT in my system and found it to be an excellent performance card for the cost - on a 19" display at max settings i'm sure you'll have minimal issues with either an 8800GT 512 or an 88800 GTS 512