light bar adjustable mounts

So I've been on the search lately, I have a first gen with a ARB up front. I want to utilize the top two mounts on the bumper to mount the light on. But I'm wanting a bar where the mounts slide back and fourth on the body of the light for total adjustment on how you can mount it. I swear a while back I saw something like this but can't find anything like that now. Does something like this exist? I imagine something like a weaver rail like on a gun, run the whole length of the light body. That would make mounting much easier having that flexibility for mounting points.

 

So I just came across totron led light bars, their SR series look like what I need. But their website has little to no info. Prolly a sign...... but does anyone know if these mounts are adjustable on the light body itself or are they stationary?

Still needing info on any others as well??