Kaizan foam is not gonna look as nice as thick dense quality foam.
Go with dense foam and forget using a knife or hot wire cutter. I've done it and it looks like shit.
Trace your tools and have a company laser/water jet cut the foam.
Also if you want to make it look even better get a 1/4" thick red foam and glue to the bottom of the already shadow cut 1/2" or 1" black foam.
