I'm all for avoiding VGA if possible... but you can run both an HDMI and DVI connection at the same time on your cards?
You can get one of these cables per dvi output, they convert to hdmi for the monitors: http://www.newegg.com/Product/Product.aspx?Item=N82E16812270114
Bummer! Hope he hasn't bought the monitors yet. Otherwise, he'll be looking for video cards with 2, HDMI ports... not common. Never imagined a monitor being so cheap as to include a VGA but no DVI port.
He'll need an active displayport to HDMI adapter too, which are around $30. Not to mention no VESA mounts if he wants to put them on different stands.
For the 8400 GS, no. I haven't tried it because I use mostly VGAs on my monitors. Only a few DVI direct. The rest is to use DVI-VGA adapters. For the 8400 GS card, I think it is: either DVI + VGA or HDMI + VGA
Just a lot of head turning. Much harder for 1x6. Very hard indeed since those are 27-inch monitors... 1x6 would be quite impractical.
I've got the 2gb version of this one, as a second card, runs silent. http://www.newegg.com/Product/Product.aspx?Item=N82E16814125451 Gigabyte is pretty good it seems on video cards. Just noticed mine says "overclock version". Runs silent evenso, factory overclocked to 975mhz. I like this model, as it has two mini-displayports.
There's a reason Nvidia Quadro NVS is the leader in "4+ monitor display" setups. They designed the cards with the EXPECTATION there would/likely be 4 monitors or more running from one workstation.... and running all day long (avoiding fans where possible).... been selling the NVS line for >10 yrs.