purchasing and registering in the US
 

I have just joined and appreciate all the posts. But still have questions.
I am travelling with mates from California to Florida on a big Harley. I am researching how to transfer title and register the bike which I will buy. Originally I had planned to buy and register in Florida but now understand that this would be difficult since I won't be in the state for the process and it has to be done in person (?). So now planning to register in California. Can anyone confirm for me that all I need is a Cal address, Australian motorcycle license, US based insurance. Any suggestions or traps that I should be aware of.
And how about selling the bike at the end of the journey; also any suggestions or traps?
Thanks