I have just what you want (English (US) and Spanish).
I followed this threat -->
http://www.blackberryforums.com/gene...ee-memory.html
Then at /Program Files/Common Files/Research In Motion/Shared/Loader Files/8100-v4.5.0.124_P2.7.0.92/Java, I removed all the files that end with "_en_GB".
Buala the English Great Britain language is gone!