I'm definitely not trying to stifle your creativity, but if you've done more than reading about fiberglassing, you'll know that it's a bit on the expensive side; it's very messy; the chemicals are very flammable and toxic; and the dust from sanding it is very abrasive ( gets in your clothes and gives you the "itchies"). And if you should happen to mess it up, it's like burned money.
If you are on a budget, and not in a big hurry, you might want to go ahead with some other aspects of your project, while searching for a used or new fiberglass hood. I don't think they're too expensive anymore, and certainly more cost-effective than making one from scratch. You can always do the opening for the carbs yourself.
Again, I'd like to see you learn a craft like this; but it might be good to start off with something small and simple......just to see how it goes, and if you really like to do it.