There's no reason to tell people to avoid 16:10. As a general rule, most companies higher-end monitors are 16:10 anyway. If you wan't to connect a console to your monitor, then you don't need 16:10, but it won't hurt (you'll just get black bars). If you want to run PC games on your monitor, there's no serious downside. Sure, not all games natively support 16:10, but not all games natively support 16:9, 4:3, or 5:4 either. Effectively zero games support the aspect ratios produced by using multiple monitors, that alone is no reason to discredit using them. You can always force a game to a given resolution/aspect ratio, even if it doesn't "officially" support it. That said, there's nothing wrong with 16:9 either. Choose whatever aspect ratio you prefer. Some want more vertical space, others value horizontal space more.
As jaguar said, 8ms is not bad at all for gaming. I used to play a lot of UT on a laptop screen with a 16ms quoted response time, and never noticed ghosting at all. The asus looks to be a good option, as it's somewhat cheap and doesn't use a TN panel.
A few other general options are 120Hz TN panel monitors, those can display a 120Hz image rather than the standard 60Hz. It's best to find one and see for yourself if you notice the difference. If you don't go fora 120Hz monitor, you could find a VA panel (like the asus) or an IPS panel monitor also within your price range. Here are just a few.
IPS/VA monitors: (23'', not 24'' seems to be the standard size for 16:9 IPS panels, I'm not sure why)
http://www.newegg.com/Product/Product.aspx?Item=N82E16824176144 (recertified HP, 24'' VA panel, 16:10, $200)
http://www.newegg.com/Product/Product.aspx?Item=N82E16824005234 (LG, 23'' IPS panel, 16:9, $250)
http://www.newegg.com/Product/Product.aspx?Item=N82E16824116421 (Viewsonic, 23'' IPS panel, 16:9, $290)
http://www.newegg.com/Product/Product.aspx?Item=N82E16824236122 (ASUS, 23'' IPS panel, 16:9, $210)
http://accessories.us.dell.com/sna/productdetail.aspx?c=us&l=en&s=bsd&cs=04&sku=320-9270 (the often-recommended U2410 is out of your budget, but this is dell's 23'' 16:9 IPS model. $250 from their site)
http://shopping1.hp.com/is-bin/INTERSHOP.enfinity/WFS/WW-USSMBPublicStore-Site/en_US/-/USD/ViewProductDetail-Start?ProductUUID=gV8Q7EN5rFYAAAEtWmVVIOG3&CatalogCategoryID=yP4Q7EN5.w0AAAEu6fw.zwd2 (A tad over your budget at $425. HP, 24'' IPS panel, 16:10)
120Hz monitors:
http://www.newegg.com/Product/Product.aspx?Item=N82E16824009222 (Acer, 23.6'' 120Hz TN panel, 16:9, $350)
http://www.newegg.com/Product/Product.aspx?Item=N82E16824236104 (Asus, 23'' 120Hz TN panel, 16:9, $350)
There are obviously a lot of options out there. It would be easier if you specified a few things, like do you prefer 16:9 or 16:10, do you want 120Hz or not, and are you more concerned with picture quality or monitor size?
For $450ish you could get three cheap 23'' TN panel monitors if you wanted to (dual 6950s should be able to handle that), or you could get a single 23.6'' 120Hz panel for ~$350, spend around $300 for a 23'' IPS/VA panel monitor, or spend ~$375 for a 27'' TN panel monitor. It's kind of up to your preferences.