[jweb]

If you're worried about water on the jute you can get jute pad with foil on both sides. I doubt a small amount of rain is going to make it through the carpet and jute to your floor.
Jute with foil on both sides (this is what is in my '51 and I will use the same stuff in my '64 Suburban): https://www.perfectfit.com/15269/154...-Solution.html

If you are looking to spend a bunch more money there are several options here:
https://www.secondskinaudio.com/

If you're worried about rust, just remember before you over do it how long the original floors in your truck lasted. Most people are building something that is garage kept and not driven every day. So it will be solid for a very long time.