I've just finished fitting lowered/uprated springs & shox to my 1994 Golf III VR6. The kit I bought was Sachs/Boge Turbo (?250), but fitment of the Koni/Bilstein kit and others (excluding coilover kits) is similar.
For anyone else reading this who's interested in lowering/uprating suspension on a Mk III, here's the benefit of my experience..
Two types of suspension are fitted to golf mk3 models, "plus" suspension (GTI 8V, GTI16V & VR6) and "standard" suspension (all other models). Golfs with "plus" suspension always have the 5-stud wheel fitment.
The "plus" suspension underwent a specification change in 1994, but the only differences are at the front - On earlier cars, the top of the spring is tapered and uses a smaller spring retaining cap.
Some suspension manufacturers list two kits for GTI/VR6, one for ->'94 and one for '94 onwards, but other kits (including the Boge Turbo) only fit the later type suspension.
If you've got a 1994 (or earlier) model, I'd recommend checking your VIN with VW to check what type of suspension you have before buying & fitting your new springs. It's most annoying to spend 2 hours taking everything apart only to find the front springs don't fit...

Fortunately, later type suspension kits can be made to fit to an earlier car by just replacing the front upper spring caps (?20) and the front top mounts (?35). Not a big deal, as you'll need to replace the top mounts anyway.
At the rear, the bump stops always need to be replaced, as these are exposed to moisture and dirt and perish quickly. Replacements are ?17 each. The front ones are not so exposed and should be OK unless your car has done high mileage.
All prices quoted are for the genuine VW parts because you really don't want to use cheap copies on such a safety-critical part of the car.
Top nuts (front and rear) also need to be replaced, but these are included with the Boge kit, and should be with other kits as well.
Here are all the tools I used:
For front top mount:
21mm Spark plug socket (included in most socket sets) to hold/turn mounting nut.
24mm open spanner - to hold/ turn spark plug socket...
7mm allen wrench - to hold/turn central shaft.
General Stuff:
Standard socket set
Standard ring spanner set
Spring Compressors (?15 from Halfords)
2ft breaker bar
Torque Wrench
Once the new suspension is on, you will need a full 4-wheel alignment professionally done (~?80), otherwise the ride quality will be poo and your tyres will wear unevenly.
So total cost of the job is at least ?165 on top of the cost of the suspension kit, but budget for ?200 in case you need to replace spring caps and/or front bump stops.
For the wheel alignment (or preferably the entire job), I can highly recommend AMD in Bicester. They are professional, fairly priced and really know their VWs.
http://www.auto-amd.comWith everything all put back together and adjusted properly, the car handles like a dream. OK, the Koni kit would probably be better, but it's a MASSIVE improvement on standard and looks good too.
Nick.