The question you should ask yourself above all else is... what resolution do you want to run your 4:3 games at? 1024x768 or 1280x1024?
Personally, I would not go with a 19" Widescreen LCD. If you can afford it spend the extra cash and get a 20 or 20.1" widescreen, or just go with a standard 19" LCD.
First, your resolution on a 19" widescreen is 1440x900 pixels. If you run games that only support 4:3 aspect ratio then your gaming resolution will be 1024x768. Also, 1440x900 is not *true* widescreen as its aspect ratio is only 14:9 and not 16:9. A 20" or 20.1" widescreen is your best bet, as running in 4:3 mode you still get 1280x1024 which is just as good as your standard 19" LCD. Also, most 19" LCDs (especially the cheap ones) do not have a DVI port on them. Plus 16:9 widescreens are 16:10 which are true widescreen displays with a little overkill.
Second, to avoid "stretching", NVidia and ATI drivers both have a setting to configure the monitor scaling of your flat panel. This does, however, requite two things. One, you have to be using your LCD with a DVI cable. Except for the highest-end IGPs, this also requires that you be using an add-in video card and not a sappy little IGP. Taking these two into consideration, within your Flat Panel Settings of your display driver's control panel you can set your monitor to run with "Fixed Aspect Ratio Scaling." This will allow all games that only work with 4:3 aspect ratios to run in exactly that ratio. You will have black bars on ether side of the image, but for myself it is a small price to pay for the extra desktop space. Also, I use a Sceptre x20 Naga III. All games I have run on it have not experienced any tearing or ghosting.