Yup. It really comes down to 2 things, budget and space.
Do you have a spot picked out for the tank?
Do you have a spending limit for the entire setup?
Within those two factors, get the biggest tank you can. Bigger tanks tend to be more stable and forgiving of mistakes than smaller tanks. Not to mention your stocking options obviously increase with tank size.
Do you have any idea what fish would you want to keep?