I am not being rude, but you are. I know the reasons, but you do not know why I am still asking the question, do you? No. If you cannot answer the question yourself, then I will give you an answer.
You can mix armor types, enchant any type of clothing and create the look you want. You are not forced to get bonuses. You are only stopping yourself from getting the look you want.
If you are worried about not having enough armor and like the heavy armor better then why not go for heavy armor right away?
How is that, Stigwa?
I do not care for any bonuses, but as I said, the OP was looking for a cool looking light ARMOUR helmet so that he could get the bonus.
Personally I run about in whatever looks cool and somewhat realistic. I much prefer things like steel and hide to ebony for example.
Of course, you can mix and match as much as you wish to, and use enchantments to make up for the loss in armour rating. But when he specifically asks for a helmet, why go on about hats, heavy armour and enchantments?
If some people want the bonuses and care less for the aestetic, let them and try to give them a suggestion for them to get the bonus.