For motors, Brushless is the most common these days. Which Brushless is obviously something you'd need to have a look at a bit more in detail based on your build so far (There's some low KV NTM Prop drives on Hobbyking.com which are supposedly pretty good and torquey for a heavier spinner like that)

One thing you will need to account for is the stability of such a heavy vertical spinner, you'll obviously want to spread the weight out to make sure it'll stay on at least one wheel, because the higher speed spinners do have quite a bit of a pull to them. What batteries/drive motors have you got for the machine, by the way?