Lowering a "non" Sport

One of the first things I plan on doing to my 4.2 is to lower it. I don't want it silly low, just lower than it is. The rear in particular on the non Sport car seems to ride rather high.

But what options have I got? I don't want to spend loads of money, but I'd like to do it right.

The obvious options seem to be a simple set of lowering springs (such as Eibach?) or perhaps fitting some second hand kit off a Sport or an S8.

Which is best, easiest etc? Are there any other options?

Thanks,

Adam