Not only would I vote for you - hopefully you get the joke - but let me help you with this question. If you're currently happy with the 8800 GT's performance @ 1080p with low-mid settings, then any of those video cards is going to give you an improvement.
I would skip the ASUS 8800 GTS 384MB card - as it's old, and only has 384MB of RAM. I would suggest, out of the options provided, the Gigabyte HD 6670. It will have 1GB of RAM, and is a fairly current card. It'll have no issues under Linux and will kick the ass of the card you're running now - by a long shot.
Do let us know how you go with the upgrade, I'd love to hear your thoughts on the huge performance difference.