There are about a million different manufacturers for L-track (sometimes advertised as O-track, S-track or Airline track), and I've used a variety over the years. If you're going to be mounting something important (like vehicle seats), then you'll want to make sure to get high-quality, heavy-duty tracks. For light applications such as these, virtually anything off of Amazon will do.
For more ideas of what such tracks can be used for, have a look at the
Cargo Trailer Conversion I built a year ago. You'll see such tracks all over the exterior.
I ordered
these tracks, and just installed them:
I left an 8" space between the tracks, using a piece of 8"-tall plywood sitting on the bottom track to support the second track as I mounted it. The wide, grey, horizontal decal acted as a good indicator of "level".
Attached into the tracks are a single stud and single ring, just as an example.
I used two 12" tracks, and wouldn't suggest getting sizes larger than that. The backer plate is supposedly 14x14", and after playing around with my stud finder I believe it. A larger track would likely have one or more mounting holes not secured into the backing plate.
I pre-drilled the holes, then used stainless machine screws (non self-tapping/drilling) in 1" length. Hand-tightened until I felt a good amount of resistance so as to not over-tighten/rip through. With silicone, of course.
The good thing about this position is that even if you ever rip out whatever you've mounted, you can drill straight through the wall and secure with a plywood backing plate on the other side - everything is behind cabinetry, so no one will ever see it.
Linear Mode
