Well you get what u pay for, although I have not heard of that shuttle brand. If you can afford $499, i would recommend going at least 19". It is NOT too big. This is the best LCD currently on the market, withing reasonable price and at 4:3 screensize.
http://www.newegg.com/Product/Product.asp?Item=N82E16824116277
http://www.newegg.com/Product/Product.asp?Item=N82E16824116277