I'd probably look at getting something from Acer, Samsung, ASUS, BenQ, Dell or LG instead to be perfectly honest with you. What kind of money are you looking at spending?
The ViewSonic is 1600x900 and the Lenovo is only 1366x768 - you should really look at getting something a little bigger than about 20" (maybe 22" or 23") and also aim for 1920x1080. Most 22", 23" and 24" monitors these days are 1080p and that's going to be so much better for you than 720p or 900p on a desktop monitor. So I'd recommend looking at something in the 22-24" region from one of the manufacturers I listed above and make sure it's 1080p.
As far as cost goes, you can spend a lot, but really 22-24" 1080p monitors are getting quite cheap now so there's no real reason not to look at that size and resolution. I think LG and Acer in particular make monitors which are good quality and good value for money.