So finally had time to get my mining rig fixed up (mobo fried, RMAed it, been busy with work and such) and I've got this kind of working.... weird issue going on though.
I get through bios/can select what to boot into through the BAMT screen, then it does it's loading stuff.... and then no more monitor! None of the graphics cards (5 5830s) display anything if I plug them in. I am able to SSH into the machine just fine.
I had similar issues with 5830s and Linux. Nothing would appear on the monitor (from any video card) until it finished booting into X. Not exactly sure why, but it did show up eventually.
I'm pretty sure the problem is your overclocking. Most of my 5830s (I have 15) are not stable at 970. In windows with Trixx where I can bump up the voltage a little they are stable at 970. But at stock voltages the majority of mine (sapphire extremes) were not stable.
If one card doesn't like being at 970, it will mess up the entire system. I'd put them all to 900 just to get things working. After it's run for a few hours then I'd put it at 950. That's where I found all my cards worked fine at stock voltages and still got 304 mhash.
Also what kind of power supply do you have? Have you run this system on Windows? As in you know all the hardware works fine and it's a BAMT issue.