Spax will make you telescopic dampers or coilovers to your spec with any combination of fittings at either end. If I remember rightly they aren't that expensive either. I was going to look into getting some CSX coilovers made for the rear but I never got round to it.
Just search for Spax KSX for their custom dampers.
Edit - Try this link on for size
http://www.silverstonetuning.com/pdf/KSX.pdf