Copying from another thread of mine, 1st thing I want to say is there is no 100% correct car to use its all about feel and learning the car.
Don't do 4wd 1st of all, I don't want to cause flame wars, but just don't things will be better off in the end if you avoid it. :S
I personally say get an FC rx7, with abouts..220hp, (I say this is a possible car since omeone I know whos not to much into drift enjoyed this car at my palce when sideways, but again there is no perfect car.) put an LSD in and its simply a matter of learning car control, drifting is about balance, largely between the throttle and steering input, I recommend sticking with 1 car and 1 track, since learning a bunch of different tracks and cars will just make it harder for you.
There is NO car that will just work and be a holy moment of drifting perfection. Think about this, You are trying to learn 3 things.
1) How to drift 2) How the car feels and behaves 3) the track. Now does it not make sense to lower your workload? Pick a single track..I personally say Tsukuba since most of the corners are similar but there are a couple to mix things up, and you can drift laps..rather then going back and forth on Suzuka. The car This part I cannot stress enough pick 1 car and 1 car only, so many people I see hopping from car to car and it does NOTHING to assist in learning, find a single car you like and stick with it, there are 2 main types of cars small nimble cars, easy to get sideways usually but easier to get to much angle or overcorrect and snapback, and larger more sluggish cars harder to get sideways but easier to maintain it sideways (providing it has appropriate power.) since the steering isn't so quick to react in these cars its generally harder to get snapback or get to much angle. So you get those 2 things..you learn the track layout and surface and you learn how your car behaves when cornering that leaves you with only 1 thing to focus on learning, drifting. See the logic?
As for the actually drifting its a matter of approach a corner at a speed you would normally go at it for gripping. (Or you can as I call it walk to the corner by going at a speed your comfortable at and let the car roll up.) At that point give the handbrake a tap..just for like...1/4 a second if that and turn in at the same time, (There are other techniques to get sideways but this is one of the most predictable.) at this point the tail will swing out and give it gas to throw it out more. At this point you do what I call "catching" the drift where you let the rear slide as much as your comfortable and then apply countersteer, I use the term catching the drift cause when you get the steering right the car will hold the angle suddenly if you get the countersteer correct. the last step is through the corner start feathering the gas gently, not to much to spin it. but enough to not get grip in the rear again.
That's basically it, but in the end no amount of reading can prep you, it just takes alot of practice to get it down correctly, don't give it and keep going at it, if you get frustrated take a break and come back in 10 or so min.
Some stuff that's more exact to your problems you states
Speed: I covered above
Gear: usually the same gear as you would take when gripping, if you notice RPM dropping downshift 1 gear. (this is what I call bogging down, the engine simply does not have the torque to keep the wheels spinning)
How to prevent overcorrecting: experience..there is really near no way you can get a fool proof way to do this, its just all in learning how it feels when you get it right.
For your 1st complaint about the comfort hards..do you have driver aids off? The only causes for the car coming to a stop are this. 1) you have driver aids on, 2) you are getting sideways and not giving it gas, you need to give throttle to drift. 3) you are getting to much angle. In the 3rd case I refer to it as a stall, there is just way to much angle and workload for the engine and again it will bog down.
but i want to help you like someone helped me weeks ago and now i can't tell you how much i am having fun.
i am still using a controller 
