That black "underwear" is called body amour/ or a body suit.
And the idea about you choosing the name and appearance of your clone doesn't sit to well with me. Don't get me wrong, I do believe it to be a good idea, however, it doesn't fit with the story line. Most people who played and enjoyed Republic Commando don't want to play a made of EU game. They want a continued story line with some of the secrets left in the first game answered.
That would make a good mod though.