Vacuum Infusion questions

[JohnC]

I saw a couple of builds on the other forum that used infusion to build from the hull up. It looks to be very stiff & light-weight. I'm intrigued! I would like to make some parts this way and I have been doing a lot of reading and watching videos on the subject. It looks doable in a garage with a small investment in equipment. I have a vacuum pump but I need the hoses, trap, fittings and some specialized consumables (vacuum film, flow medium, peel ply). Building molds seems to be the biggest part of the work.
I was wondering about the best core material to build a console & hatches. PCV foam, polyurethane or polyester? Most things I have read say PVC for structural and PU for insulation but I'm not confident in that. The stuff I have read doesn't recommend a density of foam core either.
I also don't understand if its best to do a gelcoat skin and CSM and let it cure, then setup the infusion on top of that or can do it all at once. I plan to do some small parts as some trial and error would be needed.

Has anyone done any infusion projects on this forum? I did a quick search and didn't see any projects with pics. Any help or input is appreciated.