@cristianmos
At the moment I don't have a lot of time to work on this. For now you can simple edit uc_decimal_quantities.module and change the following code:
define('UC_DECIMAL_QUANTITIES_FACTOR', 100);
define('UC_DECIMAL_QUANTITIES_UNIT', 'm');
define('UC_DECIMAL_QUANTITIES_UNIT_NAME', 'metre');
define('UC_DECIMAL_QUANTITIES_UNIT_NAME_PLURAL', 'metres');
define('UC_DECIMAL_QUANTITIES_STORED_UNIT', 'cm');I might get around to setting this up as a contribution if I get time.