What motor should i buy?

Hi guys, i need to make a robot that follow a line and have to cross a 30° ramp. What motor should i buy? Should i use wheels or mat?

I search for some motor, and i liked that one: http://www.pololu.com/catalog/product/1105 What i need to install it? its complicated?

Not enough information !!

Weight of robot Speed of movement over the ground Size of wheels proposed Number of drive wheels Number of drive motors Intended operating voltage

I don't know the weight :( The speed don't need to be high. 2 wheels with motors I don't know the size yet, but 70mm

Look this video, the robot have to do this in 5 minutes. http://www.youtube.com/watch?v=s1UZK18NGjc