Jorge, don't take this the wrong way, but Hunter is far better served by going to a specific speed shop that has lots of experience with Audi's. There are quite a few great shops in and around San Jose. But, before you spend a dime, Hunter, spend some time on one of the Audi forums for the A4. Read through their suspension forums, there will be a ton of threads, read as many as you can stomach. A week later do it again until you know what you want done to your car and the specific brands that will work for you.
You need to understand there is a sliding scale with many of these mods, from a nicely lowered car that drives well and has little increased road and suspension noise to the wrong modifications or brands causing increased road noises and harsh driving characteristics. Reading through the threads for suspension mods will reveal a ton of good and useful information so you don't end up looking and feeling like that dumbass 18yo kid with the slammed Honda and bruised kidneys.
There are good places in just changing out the different grommets that hold the suspension together, almost always made of rubber. Change these out for polyurethane units and you'll gain a ton of firmness along with better feedback in steering and suspension travel, it will also transmit more vibrations through the suspension and back to you in the cabin in the form of increased noise. The trick is picking the ones that matter and the ones best left stock for sanity sake.
Also, I would highly suggest staying away from coilovers, I tried to avoid saying that in the previous thread but for a daily driver, it makes for shit ride quality in the best of circumstances. There are very high quality units out there, in the tens of thousands of dollars for a single set of four units and then there are the units in the sub two thousand dollars. Some are decent but most have half assed valving stacks, the stuff that damps the compression and rebound. There are tons of options to replace the struts in your car to something with at least rebound damping adjustment, Koni, Bilstein and Ohlins. They cost a bit and are good at what they do, slow down the amplitude of the springs action on your car while driving at speed over imperfections in the road.
I would also highly suggest not reducing the cars suspension travel too much, it has adverse effects on the cars manners for daily driving and makes every square edged on the road, think every stinking transition on on the concrete seems of 880 you'll probably be hitting the bump stops which means a nice harsh kick to your kidney. I am not familiar with the Audi aftermarket but it would take me less than a week to get the back ground, you should be the one to decide what it is you actually want from the car and the best path to get, what brands and what approach to the end result.
If it was my car, I would do exactly what I suggested previously, replace the springs with a slight drop, ones with less than an inch drop. While lowering the car further into it's suspension throw, you need to increase the springs on your car to a higher rate to compensate for the lost travel. Once you go to higher rate springs you need a higher quality strut that is capable of dealing with higher forces to dampen those new springs. The stock struts will fail pretty quick with anything above stock rates. With stock wheels the stance of the car will have a new attitude. With say the Koni adjustable struts and the slightly lower and stiffer springs you will have a better turn in and more responsive chassis, it will feel alot more lively. After that replace the front and rear sway bars, end links that are solid metal like the Whiteline units, and polyurethane bushings for the swaybar mount and you will be grinning from ear-to-ear from that massive turn in, snappy steering and down right track car you now have. If done right and you get the balance of firm and yet still supple, the car will be a good daily driver, not beat you up, and handle like nothing you have driven before. The only thing between you and your perfectly stanced and track master Audi is a good chunk of change :-P
EDIT: Holy shit, I think I took two dumps in making this post
Also, Hunter, if you can not tell I am thrilled that I finally took the time, bought the items and built my new WRX, just wish I hadn't waited seven years to do it. That Audi is a great platform but as it sits, has a very soft suspension and tends to wallow through high speed corners, think on and off ramps. Stop buying computer parts for two months, you could do that Audi three times over.
