RE: Best Drift Car under $800
The chassis that is used the most at the local drift track here is the Yokomo DRB (the Hyper SSG is popular as well).
It isn't the cheapest chassis out there, but it has incrediblecounter-steer capabilities.
You won't need a super high speed brushless motor or any LiPo battery pack over 2S if you are using a counter-steer setup.