There are very few differences between eco and sportsline - The eco had the bean can exhaust and the no oil friction shocks. The considerably later sports line has the side pipe and the oil filled shocks. Most other parts are the same. There is a massive void between the skills used for driving on road and off road - unless you get the set up and technique right for on road, the car will spend most of the day spinning out or going up it's own arsenal.
Tyre wise, the lower the number/letter should in most cases denote the softer tyre i.e Softer 5,10,15 Harder Softer A,B,C Harder
A proper track with clean tarmac will provide infinitely more fun than a carpark.