Another thought.
If the worse come to the worst, you could use something like this, and rewire it to take it all from the molex.
The disadvantage of that is some PSUs have separate rails for the EPS 8 pin connector and normal +12v stuff, and it might throw the balance of the two off.
With something like a Tagan, this isnt an issue as they will auto switch between split channel and combined, but some PSU's might not like the load on one rail.
Like I said, not the ideal solution, but it should work if needed
edit - just found the 30cm one too. You could buy that, snip it to make it shorter? That wouldn't touch your PSU and at a worst case would only loose a few quid