we are doing it. and i can assure you, it isnt easy. its a simple concept, but it when you start getting into all the tooling and shit that goes along with it, it quickly ramps up to be a massive amount of work. my advice, is if youve got a real reason to, like some radical new design that is not commercially available, then go for it. but the first step is research, lots and lots of research.
and about vacuum presses. i have used them to build skateboards. they are a pain in the ass. and, you cant press anywhere near as high of pressure as with a pneumatic press, and they produce kinda crappy quality. i think the only way to make a vac press usable for skis would be to build an autoclave to boost the pressure.
heres some pics of our press, almost done.
this is an entire summers worth of work^