I don't really see the point in going with a full harness setup in a street car. Maybe if it sees its fair share of autocrosses and track days it's sort of worth it but otherwise I wouldn't bother.

If I was getting harnesses however, there are plenty of companies that have actual distribution channels in the USA that sell quality harnesses. It's not like you need to import them from Japan or something--people do in fact go racing here too.