Re:
I'm 99.9% sure that you wont find a 27.0 X-lite post.
They came in either 25.4 or 27.2mm diameters.
If you want a 25.4 and then run a shim with it then drop me a pm as I have a lovely black clik-on in that size, and may even have a 27.0 shim too somewhere.