If what I produced demanded machinery this size, from the off, I would seriously consider used machines; full size sliding saws can be particularly bargains, if you’re prepared to handle the logistics of moving one, but the same goes for other large machines.
I make things for pleasure, but my machines are sized to take just about anything that I can handle single handed, and I’ve less than £1500 invested in my Startrite bandsaw (£70), SCM spindle moulder (£200), Sedgwick cabinet saw (£800) and Dominion P/T (£400). Together with my track saw for full sheets, I can make some pretty big stuff.
My tan brother, however, makes his living from this stuff. He has some very nice gear, with automation, stored settings etc… but, he started with track saws and a mitre saw. And expenditure has been more than matched by extraction, compressed air, assembly and finishing spaces and simply bigger premises.
What do I take from this? That I’m confident that you can achieve your current machinery goals for a lot less, by buying second hand; you have the time to find the gear that’s right for you, and there will undoubtedly be other things to spend the money saved on. An alternative path is to start small and grow organically, but beyond that, I don’t know the market you’re selling into etc, so can’t comment on the viability of the business etc.
Good luck!