I would think it would not be to hard maybe contact creative acrylic to make the glass or use lexan or plexiglass. then you just use alum.chanels to make the frame and bolt into place.... thats at least my thiughts on it. ive thought about doing the same thing on mine but have to many other projects going.
I would think get the hard top done first then do the windsheild. but if your looking at making what x-shark has then thats a while nother issue. I have accualy thiught the same thing but I kinda like the wind and being able to look above the windsheild or threw it so im going to stick with what I have..
Get the hardtop done, then go see Billy at the canvas shop on gulf beach hwy and look at the glass called EZ2CY. Its pricey, but good. Trying to modify all that framework will be costly, and you wont get it back. EZ2CY is not a soft glass like eisenglass, its stiff and clear as can be.