LCD Flat Panel Monitor Resolution and Brightness

Hi, I have a Dimension 2350 and do some photo editing. I presently have a 17 in CRT monitor but find that the settings do not allow me to set it bright enough or sharp enough. I am looking for suggestions for types of flat panel LCD Monitors that I should purchase. Would a contrast of 450:1 and a brightness of 250 cd/m2 be sufficient. What screen refresh characteristics would also be best.