I wouldn't race either of those. Problem is your not going to find anyone else racing either of those vehicles so its going to be hard to get setup advice, and parts if you break them. No reason to start with an un-needed handicap.
If you want an easy and affordable way to get into racing, pick up a RTR Brushless SC10. You could also go RTR brushless B4 if you would rather race buggy, but the SC10 is easier to learn to drive fast on a track then the buggy will be.