If you have room go bigger, the print can be hard to read on small monitors.  If you can go compare them at a local store.  Minimum for me would be a 22" but prefer a 24" or 27".  Staples has a 24" Dell for  $149.  Our local Sams Club has a nice selection of monitors at a good price.  


Here's a nice 23" for $119 after a $20 rebate.