That's quite a list! First call should be to Regal &/or a Regal dealer.
My guess is the windshield parts and swim platform will be boat junk yards.
You may have to "beg, borrow, & steal" those parts. It's a 21 year old boat.
Canvas can be local or possibly greatlakesboattop.com
Local will be cheaper, but that's the last item you'll need.
I sure hope you got a terrific deal on that boat.