Other Car Rental Programs/Partners (ie. Alamo, Enterprise, Sixt) - Car Hire in Atlanta

I have never hired a car in the US before, so please can someone tell me what is my best option

1. Collect on 23 June - return 2 July
2. Staying at IC Atlanta, so do I collect from the airport? or does anyone deliver to the hotel
3. travelling around so will drop car off at Airport to return home
4. We are from UK so we need to take out the extra insurance? is that correct
5. Want to hire a Trialblazer or similar
6. Book now or leave it to nearer the 23 June

any promo codes what company would you recommend?

thanks