Subaru Impreza WRX with Prodrive Performance Pack (or PPP) which remaps the EMU, and replacement exhaust and turbo pipes giving 25% torque boost and peak power of 265bhp: 0 - 60 in 4.9 sec if you get the gear change right. Not the fastest model available but a good compromise between performance, comfort and price. It is also good for a 4 wheel drift from a standing start.
Yes, by default all road going scoobies under-steer due to the factory suspension settings, but there are numerous alternative settings by Prodrive and others that will change that characteristic, and replacement suspension parts etc. Simple 4 wheel suspension adjustment (no more than £80) is enough to remove the under-steer, but the more enthusiastic people also change springs, anti-roll bar, drop-links, dampers and suspension mounting parts to allow for additional adjustment. Just changing the rear anti-roll bar to a stiffer one will remove the under-steer because it reduces the weight transfer and keeps the front wheels in better road contact.
Lots of discussion about under and over-steer on
http://bbs.scoobynet.co.uk/forumdisplay.php?f=354, including the finer points about when under-steer translates into a front wheel skid.
Going back to the under/over steer point, yes most drivers will increase the steering in under-steer, but most will also lift off the throttle, which transfers weight forward and increases front end grip thus normally getting the car back to where the driver wanted it. This is the reason why under-steer is preferable for Mr Average driver: lifting off the throttle is the standard reaction to danger - slow down this is getting dangerous.
In an over-steering car the same reaction happens: untrained driver will lift off the throttle, which obviously has the same effect and shifts weight forward onto the front wheels. But the front wheels are already gripping fine, what happens is that the rear wheels proportionally lose whatever grip they had and the car spins, or if the wheels were slipping because of excess throttle they might suddenly regain grip when the speed matches the road speed which is the fish-tail situation. The good drivers (such as the instructors I had on my training day) will steer into the slide and carefully balance the throttle to maintain just the right amount of rear-end grip for a nicely balanced drift.
However there are obvious safety disadvantages to holding a drift on a public road: the back of the car, and potentially all of the car is moving sideways across the road which might be into another lane, the verge, armco or the oncoming lane. If the balance is maintained perfectly, then you will be OK, but the slightest mistake and if you are lucky the tow truck will get the car out of the hedge, if you are unlucky it will be coffins for you are that family of 5 that happened to be coming the other way. Even if you are holding the drift perfectly you will still be totally stuffed by an unexpected obstruction in the road, because any lift off of the throttle will cause that weight shift and resulting spin.
On the balance of things, for everybody but the enthusiast driver who takes time to learn about how to get a car into a drift and how to control it, and under-steering car is the safer and preferable option.