Welcome to TPT!
which would be best for a planted tank?
All of them!
Actually, I'd start with one of the smaller tanks so you can get down the "basics" without the larger costs involved in setting up one of the bigger tanks. Equipment and substrate add up really quickly on big tanks, and if you start with a smaller tank first, you can get a handle on what type of planted tank works for you before investing all the $$ only to wish you'd gone a different direction...
Lighting is one of the most important factors in setting up a planted tank. Light controls plant growth rates, and growth rates determine the nutrient demands of plants.
You need to decide first of all how "high tech" you want your tank to be- if you put a lot of light over the tank, you'll need to also be sure to put together a comprehensive fertilizer regimen and add a pressurized CO2 setup. High light/high tech tanks allow you to keep the widest variety of plants, and the plants will grow lush quite quickly. These tanks require at least weekly maintenance.
Low light/low tech tanks provide enough light to support plant growth, but not as much light as high tech tanks. Supplemental CO2 is often optional, and the need for fertilizers is much less. Plant growth is much slower, so these tanks are much less maintenance (and much less cost to start up).
Spend some time in the low tech forum; I personally recommend to people that their first tank be a low tech tank, as these are easier, less upfront cost, and always easy to upgrade to high tech later on if you want to.