what size grow tent should I use?

Hey everyone. I am planning a 2 plant scrog grow. I am just looking for advice before I start the grow. I was wanting to know what size tent should I use for a 2 plant scrog grow. I will be starting from seed. So my choices are a 2x2x5 tent or a 3x3x5 tent. I will be vegging with a T5 and flowering with a 400watt hps. So for 2 plants what size tent is best?

Extra room will give extra ideas...besides you never get enough room even at 4'x4'x6' ...lol