I like this idea too. Love hoods but the separate ones all have annoying dangly jewels between my eyes (please stop this) or glowing bits stuck to them, and the actual full cowls just make me look like a palette-swapped Urianger. They're a little frumpy.
I really liked the Star Velvet Hood of Casting except that it's caster-only and doesn't interact nicely with my favourite caster robes' collars at all. A simple generic hood would be great, and surely extremely easy to implement.
