Hello!
Is the radio module MOBOT-RCR-USB-V2 will be a good replacement cul? --> http://www.mobot.pl/index.php?site=products&type=853&details=7770 (http://www.mobot.pl/index.php?site=products&type=853&details=7770)
(http://s10.postimg.org/j9ul0mjkl/2015_01_09_154637_610x482_scrot.jpg) (http://postimg.org/image/j9ul0mjkl/)
Here is its specification --> http://www.mobot.pl/download/MOBOT_RCR_v2-instrukcja_obslugi_10.2009.pdf (http://www.mobot.pl/download/MOBOT_RCR_v2-instrukcja_obslugi_10.2009.pdf)
MOBOT-RCR-USB-V2 is cheap - only 15 EUR
On the First Look: No, I cant even find which RF chip they use (CUL-compatible devices need the CC1101).
Have you had a look at building a CUL by yourself (its even cheaper, if you source from banggoods or other china sellers)
http://www.fhemwiki.de/wiki/Selbstbau_CUL