I have held off on this thread for a while but after due consideration I will answer as if you want a professional output you will need to understand the following - if its just lesiure then best guess may do.
You say you want a monitor for photo editing but you dont really say what you are editing for. There is no answer that can be given without further info such as the destination of what your editing...
You may/may not know this... But when light is stored on a physical medium the components are traditionally broken down into Cyan, Magenta, Yellow and Black (CMYK) yet when representing a photo on a monitor it is made up from RGB. When using a physical medium it is the removal of colours that gives white, but when using a monitor it is an addition of colours that gives white. This is the physics of reflection of colours versus the transmission of colours.
Having worked in a production environment (over 15 years ago now so allow for improvements please) - it was always the case that the larger monitors regardless of resolutions used to give the poorer results (unless expensive) due to introduction of moiré effects introduced by the techonology. Regardless of the monitor the photo editing can be completed successfully by comparing like with like within the photo.
If you want the true representation of a photo on a monitor then this will require calibration between the monitor and the physical photo - this is done using the pantone charts -this also allows you to calibrate any application such as photoshop etc with the printed output. Typically because a monitor is a transmitted medium the colours will be more vivid however comparing and pairing the colour on the screen with the pantone colour on the printed medium can reduce this and give much more natural editing and output.
It all really depends on what you wish to do really - due to the differences between the CMYK of printing and the RGB of viewing you almost always have to work to pantone calibration tables for accuracy and even then it will often require adjustment - there is no answer or recommendation that can be made for an individual monitor in reality.
In short - if you want serious photo editing then get a monitor that is mainstream and has been reviewed for moiré effects and colour representation - then research if there is the facility to get a known pantone conversion for your output device - if there is not make sure there is the appropriate software for you to enter your own pantone conversions into both the application and the driver. This is the only way you can truly get the output you desire - if you have any friends in a printing agency/publishing house or newspaper - they can go into further detail as it is a standard issue across those industries.
Cheers
Jof