Thanks! I got the foam from JoAnn Fabrics, it is 3". They have a bunch of different ones but this was 8 feet long or close to it, and they had a 50% off sale so it was like $25, and I got a pice of 8 foot 2" as well for my Bandit for the trailer. I won't need all of that so I should be able to get the King Cat done as well.

Extra High Density Urethane Foam-3"X18"X82" | Jo-Ann

It was like that one but it was cheaper at the time, so I guess just keep an eye out. You haven't done your profile above to say where you are located so I assume you are in the US?