Okay, I dunno if you're being serious or not but i'll try and be of some help anyway.
I live up north and yes fall is cold. Sometimes there is snow too. Especially where you're going.
there is no such thing as "waterproof boots" unless you want to look like a fool from the beach wearing rain boots or something.
You need a pair of SNOW BOOTS. they're as waterproof with snow as you can get and CAN be expensive. All winter stuff usually is. And most of it you'll have to buy off the internet or when you get there because i DOUBT hawai'i has any of this.
For boots, i wouldnt worry about the brand, just get a good pair that looks similar to this. From my experience, this would be the best brand and such. Mine look like this but are grey.
You need a WINTER jacket/coat. I suggest buying one from Columbia (the brand).
Example:
as for hats, get whatever you want. All people are different and wear different styles. I'm very picky about hats, so you'll have to find you're own. They vary a lot.
As for shorts...i would say dont. lol. Wear jeans or long sweats or something. Not shorts.
If you have any other questions or w/e and you're serious about this, you can email me or IM me from msn. Just ask me for my email address or something.
Hope this helps. XX