The LEDs that you showed the link to are connected in a strip form, in groups of 3 or 5. What you want is either a 7-segment arrangement, or a 5x7 matrix. Also, they're designed to operate on a 12V power supply, which microcontrollers will need extra electronics to drive. And then the question of power--presumably this thing has to operate outdoors. What's going to power it, and how large can the battery be? At least, you have to worry about a battery unless you believe you'll always have electricity from a building or a vehicle. Sorry that it's becoming so awkward, but there are always practical issues involved in every project.