Oh no, you should not have gotten me started on this....

You might even consider a MacBook Pro (just as I did) you can even stick an external monitor on it as you can see on this photo of my workdesk:



The monitor is a 24" ACER (you don't need a Mac monitor w/c is 2x the price). This monitor is color calibrated using that pen-like device between the MacBook and the monitor. You can use 2 monitors simultaneously but for now I find the 24" to be sufficient.

The MacBook Pro has recently been rated by CNet(?) as one of the best desktop replacement notebooks around. This gives you portability if you need it too. Costs just about as much as the iMac.

I use Adobe Lightroom to organize and post-process my photos (Lightroom window is on the screen).

I had a Nikon D70 which I gave to my daughter after I got my D200 last year.