Re hardware, I am of the same view about hardware. The MacPro is more than I really need, (did not say want!
), the Mini does not really have enough grunt to cater to my photo uses, 21MB raw files and I am not keen on the All-In-One aspect of the iMac. The 20 inch iMac does not have the quality of display panel that is in the 24" and I prefer my HP 2475 IPS panel anyway. I do not care for the glossy screens that Apple seems to think we should all like.
Apple do not seem to be interested in producing something between the Pro and the Mini as a standalone. BTW try suggesting that in some Mac forums to see how quickly you get flamed.
Anyway I ended up with a 15" MBP, maxed RAM and a couple of external HDs.
One is for Time Machine back up and the other I keep my photo library on where Lightroom references them.
I do a separate back up of my photos on another drive.
I run the MBP as a desktop with the lid closed. I have a 320GB 7200 rpm drive in it and 7200 500GB 2.5" drives are available.
If your MBP is reasonably recent it may be all you need as you already have the keyboard and monitor.