I believe Z2 for mac is the same program as for the PC. Mac is harder to program for, but anyone who has one prefers it to the pc. The machines and interface are simple, fun and beautiful! ZBrush is the same. Beautiful, fun - a plesure to use. I personally feel that they easier a program is to master the better it has been designed. You don’t have to think about how you do things, just what you are doing! ZBrush is mathematically brilliant, but you never know about it because it is all in the background.
In photoshop you can get some nice effects if you play with the color balance changing the values in the shadows midtones and highlights. You may have to lower the saturtion when you are done, and tweak the hue and adjust the contrst, but if you are starting out becoming familiar with those settings is as useful and as much fun as the filters. The key is to be subtle so that people don’t notice the work, but the image. You have an eye and am sure you will do well.
My mother who is about to turn 75 bought her first mac two years ago and within six weeks was as good (if not better) than me with photoshop! Also she and my father have just started a new business! I figure if they can do it we have no excuses!