Good chassis guys do good wiring as most will wire cars also. Just make sure bar ties into lower frame, braces up to seats, and has separate harness tabs if bolt in belts. (Which is what I'd suggest). And if stock lower frame, thicker plates should be welded over frame metal. Then tied into.
And I have cam lock RJS, black in color you can have. 5 point, with lock on nuts belt so it can't fall through seat.