Hi, been taking rearing fishes as hobby since Chinese New Year. Currently been thinking of getting arowana and i need a few advise.

My question are as follow:
1. What type of arowana should i get for beginner ?
2. Price of it
3. How big should my tank be ? 2/3/4/6feet ?
4. How about the water filter system ? how much?
5. Need to decor the tank anot ?
6. Where is the cheapest in town?

seems to be lot of questions, Arowana lovers, pls do advise.
Thanks