I have 2 20.1" dells monitors that support 1600X1200, they are very nice. I actually think nowadays though that 24" wide monitors are a better value as long as they run at 1900X1200.
If you are just playing poker I'd go for the regular 20.1" ultrasharp monitor (I'd go with 2 monitors), if you do other things play games, watch movies then I'd go with the 24" widescreen ultrasharp.
Or you can always go with a nice 3 monitor setup 2X20.1 and a 24", you'd need an extra video card though.