To be perfect honestly, Deviantart is not the best place to go for computer advice, Ive been building computers for 11 years and I see so much wrong information posted here as well as opinion based information presented as facts. I would ask elsewhere if you want computer advice. An apple monitor with IPS sounds like its going to be way to expensive. IPS panel is the way to go though if your looking for a monitor for photography. 75% less reflection is stupid by the way, an IPS panel has no reflection, just to let you know how much you would be getting ripped off.
I'm not particularly inclined to recommend Apple products for the most part - they have become more and more a mobile device company dabbling in other markets, and as they've done so they've become more and more willing to ignore their more professional users (see: FCP, Xserve, Mac Pro, Aperture, etc). Their not a company I would want to hitch my wagon to for that reason.
I'm also not inclined to recommend all-in-one computers. They're basically the worst parts of both desktop (not portable, no battery backup) and laptop (not expandable, limited power). If I want something low profile, I'd sooner have a laptop I can take with me. If that's not a constraint, I'd sooner have the expandability and muscle of a proper tower - the price of the 27" iMac is getting you into socket 2011 territory, and that's a much better platform for serious workstations.
I don't like Macs. I HATE them. They are the reason Windows is destroying Windows. The ONLY reason I have a Mac is because the screens are better. I would edit a photo on my PC perfectly. Then I would run across it on a Mac and I would find so many flaws... I never had the reverse problem. (The only flaw was in my backdrop work, Macs would pick up a discoloration on the whites and only the whites from the shadows cast on the backdrop that would be washed out on my PC screen to look perfect. I'm sure there is a PC screen out there that would do the same, but I don't have the resources to have found one.) That's why I bought a Mac. You can get that with their current Macs, or even an old one. But if you just want a computer to edit photos at the basic level, a cheap PC is a much, much cheaper, and smarter choice.
My old man bought one about 3 months ago and he hasn't stopped going on about how vivid and clear the display is under most lighting conditions throughout the day! Making me quiet jealous that I have to make do with a relatively cheap Samsung wide-screen!