I ran across some new wheels for my 2004 Mustang GT and foolishly ordered them without doing the necessary research before hand. The wheels are advertised as follows: "The front wheels are 18x9 with a 5.95" backspace (+24mm offset) and the rear are 18x10 with a 6.42" backspace (+22mm)."
In the near future I do plan on installing eibach pro-kit for a 1.5" drop all the way around. I am not sure if this will change the answers to my questions but I figure the more info the better.
Questions:
What would be an appropriate tire size for the fronts and backs? Will I have to do anything special to accommodate these wheels or will I be able to mount, balance, bolt on, and go?

(The current setup is 245/45 17's)
Just so you know what you are assisting with, the wheels are White Saleen Replicas, to go onto my White GT. I really love the white on white look and that is what caused me to order them so quickly without having my questions above answered. After I get these wheels set-up I will start getting pics up
Thanks in advance for any advise!