Going to be replacing my floors. What is good to use on the passenger side. Everything says keep away from exhaust components. All the bed liners and under coatings I have looked at have said that. Is high heat paint the best solution?

Also is there any go way of keeping heat away from the floor altogether. Was thinking about taking some aluminum and mounting it between the floor and exhaust hoping for it to act as heat shield. I'm not putting carpet back in. Was going to go with bed liner on the top side. I will have passengers. I would rather they not fry.

 

Paint only, flat black stove paint will take the heat no problem, for me always paint only. I can weld thru paint again in the future. The spray on ashphalt based coatings don't adhere well, can burn, will fall off after retaining water.
So for me, paint only.
Yes to put a second layer between your cat convertor and your muffler and the floor.
This pic is heat shield for my muffler, stainless, couple of bends, long hose clamps. Clamps right round my muffler, can transfer it to a new muffler if needed. Do the same at the cat convertor. Or do a second layer right to the floor. A small air space is best, use some washers. Use metal, alum, stainless, carbon steel.
No shield, floor runs hot, uncomfortably hot, could cause carpet fire etc.
With heat shield, floor is cool.
Caution also: cat convertors do run hot, very hot by design. Don't park in tall grass as this could be a fire starter, seen it happen.