Hi dave45,
now as you ask: there is PRS+ a firmware-addon for Sony-Readers from 505 to x50 series.
Among others it also provides Cyrillic fonts and localised UserInterface.
You can find the thread easly in the sticky part of the Sony-dev-sub-forum, or go direct to the
project-page
Installation is like installing the firmware-update, so you should go with the XP-Laptop.
The T2 supports Cyrillic.