RayRay

1. Airport bus is good to have one piece of luggues, then you can walk to where ypu going to stay. Fare is around HK$30.-
2. Airport train is good to have two pieces of luggues. Then you may have to take MTR or taxi to where you going to stay. Fare is around $80
3. Taxi is  good for 2 persons and 4 pieces of luggues. It take you directly  to where you going to stay. For Kowloon, around HK$300, NT around $400, and not sure to HK Island because no experience.
4. Never try limo, and I have been told that is around 600-700 for a van similare to our SUV.

Good Luck