To be honest, if you just want to hook 4 monitor, dual video card can do the job. Getting a full tower case is not necessary.
CM 840 - ppl complaint about the 5.25" bay at the review...
i need about 192 MB of memory for every monitor, im going to be running 3 monitors to start. theres a chance i will eventually upgrade to running 6-7 monitors
Since you are running workstation, you probably not gaming.
I think you could get 2 x ati 5670 to hook upto 6 screen. but remember to get a crossfire motherboard.
Why 192MB of memory?? where is this coming from??