For this you will need 500 mine cart rails (1 block = 1 meter), which is about 8 stacks of 64. The amount of powered rails you use in your track is up to you- if your track is flat, I would use a powered rail with a redstone torch about every 40 rails.
You are going to need a lot of iron and some gold, as well as some sticks and redstone. You can build a long row of blocks in the air and lay out your track on top or just build through the landscape. Either way, you need to ride a mine cart from one end to the other without stopping.