i have various pci-e extension cables i can sell, all brand new, but i will personally test them all first before shipping if requested. a normal extension cable is 19cm found at many places, but i also have 12cm cables for the purpose of reducing cable clutter or easier to manage. the 26cm should be long enough to 6-8 card racks, or if you just want to extend longer than what standard cables provide. i believe i'm the only one that sell them in custom 26cm and 12cm long:
pci-e x1 cable standard 19cm: $7 each
pci-e x1 cable 12cm: $9 each
pci-e x1 cable 26cm: $9 each
pci-e x1 to x16 cable (v1 or v2) standard 19cm: $10 each
pci-e x1 to x16 cable (v1 or v2) 12cm: $12 each
pci-e x1 to x16 cable (v1 or v2) 26cm: $12 each
pci-e x16 cable standard 19cm: $10 each
i will add a custom molex power connector to each of them for an additional $6, just tell me how long you want the power cable to be. if you don't already know the purpose of doing this, it's so that the power drawn through the motherobard and pci-e slots now gets drawn directly from the PSU. doing this is better for your motherboard and certain PSU wires, and adds stability to your GPUs.
SHIPPING: $2 for the first one, 50cents for each additional item within the US. International is $5. i do my best to ship same day of payment, or the day after, depending on what time i receive the payment. It takes 2-3 days to receive the package within the US, about a week in Canada, and 1-2 weeks for the rest of the countries.
additional info on the cables: the pci-e x1 to x16 adapter cables comes in version1 (v1) or version2 (v2). they're different in only the connection heads. v1 is just a standard x1 cable cut so that you can insert it to a x16 pins of the video card. v2 is not cut, but comes standard with a x16 slot to connect to the x16 pins of the video card. they both work exactly the same, it's just if you prefer the extra long connection slot or not. the custom molex power connector wire is soldered onto the 5 spliced wires of the extension cable. this soldering instead of just crimpling provides a little extra durability as well as reduces any voltage drops across the connections. i used extra thick 16guage black wires for this.
now my references: i have 120 feedback on heatware, and ebay has 52. here's also a handful of people i've had transactions with on this forum:
https://bitcointalksearch.org/topic/m.472425