I used US AOPA without a problem.
All I did was put the address as my name c/o where I was renting from. Did it a week or two before I flew out, and my insurance documents were sat there waiting for me when I arrived.
Obviously, it's polite / sensible to let them know to expect some mail for you!
My cover (at $180) was for the deductible and some personal liability insurance. If I recall correctly, the deductible insurance bit was $99 and the rest was the liability insurance.
One other thing to bear in mind is that almost all standard travel insurance policies exclude GA flying. So make sure your travel insurance is in order or you may end up with an absolutely horrific bill if you injure yourself.