Geezer,
Did you not receive the screws that came with the e-track? I used the same size screws to mount the wheel chock for my motorcycle and tie it down with to the e-track, no problems. I also tote around a jacked-up golf cart, one strap across the middle to the e-track.
Since the underbelly is insulated (or at least covered) for the length of the coach drilling all the way through the floor would be difficult.
BTW, I use the Codor pit stop/trailer stop because it is removeable and just leaves a small bracket on the floor.
Here is a link to the Condor. I bought it directly from Condor, but don't have a link to their site readily available.
One of these days I need to take pictures with everything loaded, especially since we put bunk beds in the back!!
Hope this helps!
Cheers,