I got my Kirkey 47's and new harnesses. I bought new belts because a) I wanted a sub belt and b) I wanted a rotary latch. The belts are from RCI and are sold as 6 point, but you can cut one belt off and make it a 5 point if desired.
The Kirkeys have slots for either 5 or 6 point.

Let's discuss some pros n cons of 5 point vs 6 point, especially from those who have used both. Brackets and mounting and all that is not an issue, since all the stuff for the sub has to be custom made anyways.

BTW, I've never autocrossed but might like to someday for fun. Have done some drag racing and would like to thrash the Boss sometime...