I am also new to drifting, I am building a bmw E46 323CI with 2.5 Engine in it. When i bought the car, i was pretty sure the 2.5 engine was big enough - It's nowhere close to engough. So my advice is,if ur planning on getting an engine for it, look for at least 2.8.

Also, get diff welded, small wheels, and go do some practice and see how you get on, then from that you will know what u need to do next