Interior: Purchased safety harnesses.

I purchased Crow safety harnesses from Flightline Interiors.  

I went with the 5-way "kam" lock restraint with shoulder pads, 50" seat belt pull up adjustment, Y-type harness with black anodized hardware.  I chose red to match all the red accents I've applied to the interior and to make the interior more aesthetically interesting (note, that is not the same as "aesthetically pleasing"!).