Make sure you lower the car, but do it to a height you feel is appropriate for you. Some people live in areas with plenty of speedbumps and don't like have to risk hitting their sump or underside of the car, others go all out droppin' it on it's ass. Look at the "Show a pic of your MK3" thread to get an idea of what you like the look of, look in the Dub Rides section or better yet, the Projects section.
Buy what you want, and only what you want, by all accounts take people's opinions into consideration, but don't let the make the decision for you.
One final thing, make sure you ring you insurance company either first and get a quote on how much extra it will be to lower it as if this is your first car, you may find them wanting to rape you for everything you've got.
Good luck chap.