It's really hard to say. My Dell 2000FP says in the specs that it only syncs to 31Khz. Yet it does work at 15Khz. The thing is this, if you don't have a gfx card you probably don't want to get a flat panel greater than 15" anyhow.
The reason is that all flat panels have a native resolution that needs to be met in order for the display to appear clear. My Dell's native res is 1600x1200 and while it can display the native 15Khz mode it doesn't look great. It will only ever look crisp at 1600x1200.
Now I can have it always display at 1600 and just show the centered amiga res but trust me 640x200 or even 640x400 on a 1600x1200 display is super tiny.
That being said if you have a gfx card you can definitely pick up a LCD and get great output using RTG modes. I don't recommend a wide screen display at all for this case. You'll most likely never get a good res on a widescreen output.
Check the return policy for this monitor and see what it says if you can pick it up locally it may be easier to return. Otherwise go to ebay and pick up one of these 20" monitors. You won't be sorry. They have a great picture
http://search.ebay.com/search/search.dll?cgiurl=http%3A%2F%2Fcgi.ebay.com%2Fws%2F&fkr=1&from=R8&satitle=2000fp&category0=:-D
