For Drifting I recommend with sticking to trialled and true Chassis like the Tamiya TT-01 or HPI Sprint 2.
This chassis has been used in RC Drifting for a long time and has plenty of support.

The Main reason why I dont recommend nitro for drifting is
For a first time drifter, they can be as annoying as hell to tune ( I still remember my first drift meet, the guy who organised it couldn't get his RS4 to start where as the TT-01 and HPI Sprint 2 guys were sliding their brains out)
If you attend a night time RC Meet, a Nitro might not be welcomed due to the noise they generate... 10 electrics can meet and still not disturb the neighbours..

Some indoor Tracks dont allow Nitro to be run, narrowing your options for meets..

I also use Nimh to slide, Having that little extra weight in the Chassis can help kick that tail out further...

Remember Drift is not all about speed, Its the Angle and Distance of your slide that counts..