you don't need the best of the best to do this sort of thing, as it all depends on where your viewing the screen ambient light so forth are you printing out the images or are they monitor display only, what your best plan IMHO is
get a descent sized monitor say about 19" or bigger if you got the room
and get a colour analyser thing (IE colour confidence) this will analyse your display and give you the correct colour profile for the monitor so you images look good, you can also get a similar thing for printers this way the full path from manipulation to print has the correct colour profiles
you save lots over the professional stuff and it'll still be good