Lizard skin gets mixed with paint, amounts to small (micro) glass spheres that provide small air pockets within the paint, for both heat and noise reduction. (Small enough to pass through a paint gun) McMaster Carr also sells glass micro spheres

at about $20 for a 2 qt size. Should be more than enough for your cab and inner doors.
Doing my research I found there are hollow balloons and solid spheres as well as other options and they are common ingrediants in paints and other products, used as filler.
They are used in fiber glass a lot as filler and can be found at marine supply shops.
Some guys like to do it themselves and mix the balloons in a latex paint from the discount shelf. I chose traffic striping paint for its titanium content which was evident when lifting it from the shelf, reasoning density helps reduce sound.
I think the gal of micro was about $25 and the paint was $20, they covered inside the doors, and cab (everywhere a brush could reach) with 3 coats (dried between each)
A roll of 2 sided foil over bubble wrap 60"x50' was $50 at HD and was enough for 2 layers on the floor annd firewall with 1 layer in the doors and headliner. A roll of heat tape was $7 and I have 1/2 a roll left over.
I probably went over on what was needed but didn't have a need for left overs so I used it all up and the price seemed right for a Cheap A$$ Stovebolt Owner like me
