When it comes to aquariums, most new hobbyists start out with a small tank of 5g or 10g.
But a bigger tank with more water is actually more stable as things, sometimes bad things, happen much more slowly in a larger tank with more water.
My advice would be to get the largest aquarium you can...HOWEVER, there can be space issues and a larger tank will be heavier so proper support is a consideration. A 5g can go on an end table, a 10g on a dresser, but when we go big, we need more support. I once had a 29h on a coffee table and an 10g or 20g on a gutted color TV cabinet...so you can get creative by reinforcing furnisher rather than paying a high price at the fish store for a stand.
Good luck and hoping you are not on the naughty list when the big guy with the reindeer comes!