Congrats.
I'm going to offer a counter argument for a few peoples suggestions in this thread. A few people said to not worry about power and do suspension. I would say this would be a bad choice for a car you are going to drive every day as it already handles very well. Going all out on the suspension will make the car ride very harsh and be 'tweaky', that's not something, that although fun, you don't want to drive on a regular basis.
I can't offer any suggestions, as I do not know too much about the power upgrades for those cars but it looks like others had some good suggestions in this thread. That's just my opinion on what I would not do to that car.
Good luck with the car, hope you found your Golf a good home, it was (is) a very cool car.