Coruscant is portrayed with a higher-class british accents all around, so taking that to the extension, i would imagine that the underlevels would be split 4 ways between east end cockney, chinese/japanese accents, a collection of african accents, and possibly russian/german.
Brek would be of the cockney veriety, and until i can find someone better suited for voice, he is voiced by billie piper, lowered an octave or 2, but still mid-way between sounding distinctly male or female (or neither distinctly male nor female, if you prefer.) except when you make him angry, and then he puts some grind into his voice for the rudeness.