The word "Loc-line" in my first post is in blue because it is a link. If you click on it it will take you to the part page in the McMaster Carr website were you can buy a 1 ft hose segment for $8.89 online. You will need one of this per light arm. Additionally each light arm will also need:
One double socket adapter
And two socket mounts
Socket mounts allow you to secure a bolt through them so that you can affix a camera tray. They also you to secure the light on the other end of the hose. All these loc-line parts are in the 3/4 inch internal diameter size.
The tray itself is just a short aluminum bar of about 1 inch of width. It doesn't have to be that narrow, it could be wider. It just so happened that size is what I found in the scrap pile in my local metal mart. I drilled two holes on each end, one for the camera and one for the light arm.
The light is secured with a piece of stainless hose clamp. This piece wraps around the body of the light. Two holes were drilled at the ends of the stainless band to run the bolt coming out of the loc-line mount.
The loc-line company is in Portland not far from you. They do list 5 different distributors around the Seattle area here:
The Original Modular Hose System | Loc-Line - Domestic Distributors
The loc-line part numbers that you need are these:
Hose segment - 61501
Double socket - 61514
Socket mount - 60533