Hi, all. I'm new here, and very interested in the Tesla roadster. I've heard that the Ideal Range is around 245 miles, in good conditions with conservative driving. Is there only one size battery pack available with the Roadster? Or are there several different sizes/capacities? If the latter, what is the Ideal Range with each of the different packs? And how does the cost of the (new) car vary with the different battery packs?