/cgl/ - Cosplay & EGL

I doubt this is a great decision to get into the hobby, but I'm planning to do a Fire Force cosplay. I want to make the fire retardant uniform myself, but I'm not sure how to go about it.

Someone recommended adjusting the template for a trenchcoat, which seems like the right way to tackle the patterns, but the materials are something I'm still kind of torn on.

Traditionally, "Bunker/turnout gear" is made of aramid fabrics (like kevlar) and padded with fire retardant foam. Does anybody have a good suggestion for an affordable fabric that looks and feels similar, but is like, cheap (wasn't planning on fighting actual fires) and some material to make it very bulky, like in the series?