In reality what you might be looking for is a decent size monitor. I worked for a while on an iMac (29 or 27 or whatever the biggest was 3 years ago)
Currenty I am running 3x 23 1080p monitors and I feel your pain. The monitors have no decent mount and so I am stuck in a "widescreen gaming" setup for now.
I actually have a 3x23'' 1080p linux desktop, and 3 macs on 3 other monitors for work. I have communications on one (mail, office, skype, etc), some house controls on the other (music player/etc)
It is a little overkill, but I never have a "where do I put this window so I can always see it" problem
Switching between windows is really a time waster multitasker process interrupting horror. Easier to say "these 2 are for terminals, these are for netbeans, and the big one is where the site is tested in 4 different browsers"
However, what I am really looking forward to is a price drop on the 4K TVs. a 46''-ish 4K would get rid of multiple cards, converters, eyefinity, xinerama, and all the shit that complicates life on both OSX/ Linux / Windows.