y2ks2k

I know its simple, but im curious. I got a 93 hb si. i turboed it and now i want to buy hks tt type 1. the question is do i need to buy a wiring harness or does it come with it? also i want to get the one that displays in kmph(jap spec) i think. well i want to know if it will work on my car? any info would be nice