Recommendations for seat cushion

I have ordered an Emotion Mojo Angler which does not come with a seat cushion. I know I’m going to need a cushion because I’m a big boy with back and leg issues. I’ve assumed that I would buy a camping pad, cut it up and fashion a multi layer cushion out of it. But, maybe someone in the community here has a better idea. Thank you.

Catch a dozen squid and throw them in.

Check the reviews
There are a few reviews of seat cushions. Also try a search on seat cushions.

Ignore the useless snark. Everyone else here is quite helpful.