My hand is about .5" longer than you. When I was using a palm grip I found the Deathadder to work perfectly for that size.
Based on what you were saying it does sound like you would be a palm gripper if you had a proper sized mouse for it.
Any chance you could go to a Best Buy or something and try them out? Some Best Buys have mice out on display, might help you pick.
They have the G400 in stock for $30 and the Deathadder for $60 but I might be able to get them to price match Amazon. I'll go there later today and see if I can try them both out and buy it there.
Thanks for all the help!