My small rig.

5870 on a Gigabyte M68MT-D3p
The cut-off bottles are there as ducting to direct cool air in from the front (1x80mm ingress) and hot air out (120mm). I keep the side panels closed and this ducting reduces the graphics temp by 1 degC. $0 and 20mins of cut and trial and cut.
I was trying to use the PCIE-1x with an extension to plug in another 5870 but I cannot get any response with 'lspci -v' or 'aticonfig --list-adaptors'.
I even did the wire routing as mentioned here:
http://blog.zorinaq.com/?e=42By connecting B17 pin to ground. No luck.