POR15, undercoat, or sprayon bedliner?

My car is getting Lizard Skin on the floorboards (got a smoking deal on it), trunk floor is also getting Lizard Skin, I think, but wheel tubs are getting undercoated. I used spray in bed liner in one of my truck projects, did nothing for heat but it sure did quiet down the inside of the truck.....best part was a friend was just getting started in his business so it was free.....