So I am wanting to convert a 1978 Fiat Spyder convertible to electric. I bought it for the purpose and it has broken down twice since, so I will take that as a sign

I originally wanted the super 1 million+ mph 0-60 in a nanosecond type car, but am now willing to settle on something more "reasonable." This is my first project, so any advice would be useful.
Please let me know what kind of information you need about the car if you're not familiar with the type of car. It is small (Li-Fe-Phosphate!) and looks like this :
http://ettenw.org/cars/My-Cars/MyCars/1973Fiat124.jpg
1. I want to be able to drive on the freeway, at least 75 mph (so I can safely pass other cars if necessary). What kind of motor and how many volt's battery pack do I need? I was thinking 144 V is the minimum?
2. I want a 40 mile range. Will settle for less, but it would be great to get to Davis and charge with their electric car charging stations in their parking lots there. How many Amp-Hrs do the batteries need? 100?
3. What about those wheel-mounted motors I've been hearing about? Does anybody know if they are commercially available, how big they are, and how much they cost?
4. The car does not have A/C, but it would be great to have. How difficult/space consuming is it to install a compressor and other necessary components?
Thanks!