Editing Monitors

I'm in the market for purchasing a new monitor. I need a good monitor for light color grading and some video editing. I'm looking at the following monitors, which ones do you think are the best for color work? 

ASUS PA248Q 

http://www.newegg.com/Product/Product.aspx?Item=24-236-287

Dell U2713HM 27"

 http://www.bhphotovideo.com/c/product/906906-REG/Dell_469_3852_U2713HM_27_LED_LCD.html

HP DreamColor Z24x 24'' 

http://www.newegg.com/Product/Product.aspx?Item=N82E16824276096&cm_re=dream_color-_-24-276-096-_-Product

I'm leaning more towards the dream color, because of its 10 bit panel (is that a significant difference?). My budget is around $600.00. What monitors do you recommend?

With $600 you can definitely go for 1440p, and it makes a world of difference.

That Dell is a good one, so you can safely buy it, but there are other options in this price range. For example, Asus PB278Q, but basically, just search for any 1440p IPS available to you and compare reviews like those:

http://www.tftcentral.co.uk/reviews/dell_u2713hm.htm

http://www.tftcentral.co.uk/reviews/asus_pb278q.htm