If image processing is your primary use of the monitor, then better get a wide-gamut screen. However, be aware that wide-gamut screens require a proper ICC monitor profile installed in your system, or the colours of your images will be severely off. With an sRGB monitor you can get away without having a monitor profile installed. With a wide-gamut monitor, you cannot.
A quirk that comes with wide-gamut monitors is this: sRGB images, viewed through a non-colour-managed application, will appear over-saturated. That's a bit awkward but does not out-weigh the positive points in my opinion.