Prime & Paint underside questions

I did a resto/mod on a 72 Vette. I used both the POR15 to seal it then used the lizard skin to keep the heat of the floor boards. The lizard skin has 2 different types of spray that I am familiar with. One is for heat and a second one is for sound deadening. I wasnt worried about the sound so I just did the one for heat. Yes it does work very well! One thing about it is that you need a special gun to apply it. If you choose to go with it let me know as I bought one and it just sits here and collects dust.
Rod