Considerations prior to purchase
A couple of things to consider and have a plan for prior to your purchase... Are you trailering to and from track yourself? Do you have crew to help you at the track?
With trailering, a sports racer can be a little more challenging to get in the trailer than a formula car. It is quite simple to put large diameter transport wheels on a formula car to go in and out of trailer. Sports racers may require a bit more 'engineering' to get in and out of the trailer.
Do you have someone to help you set the body panels on the car? If doing it by yourself, are the panels easy to mount with just one person? If not, will you be happy installing some really nice carbon bits on your front cover and then maybe have to drag it across ground because you can't manage by yourself?
No hill is too difficult to figure out a way to cross, and shouldn't deter you from one car or another. Just know what the hills are before hand and how you plan to manage them. People will probably comment with some solutions to these topics after reading my post.