Rubber Bed mats?

Browsing and enjoying these forums for months now and have about decided on tow (haul?) vehicle, tiedown type, camper, etc.

Now I have a question regarding rubber mats. I was originally going to simply to a Linex liner and see what happens, but it looks like the consensus is a rubber mat, even if one has the liner.

So... which rubber mats are proffered? What brands should I be looking at? Thickness? Tread style?

If I get the mat and leave it in the bed, is there any need for Linex liner? Should I worry about the bed rails?

Thanks in advance for all your help!