Go big or go home with
Smart Pots.
I have been growing with them for many years. I do not recomend starting in anything smaller than what you plan on finishing it in.
When I was groiwng in soil. I took clones straight out of the clone bucket with many roots and put it into a number 10
smart pot which is about 10 gallons. I did not have to veg as long. My plants were wider than taller, had a gigantic root mass.
Leave them in the same container the whole time. The roots will pretty much eat up th3e soil in veg. In about 3 weeks of veg there will about 2 or 3 inches on top that has lowered over time. About a week before I put them flower I top dress them with about 3 inches of fresh potting soil. That gives them more nutes untill finished.
If you go with a smaller one you will have one hell of a time getting the plant out of the
smart pot to transplant it. The roots will "air prune" themselves and get stuck in the
smart pot itself.
That is why SP are better. The roots do not go around the pot. The roots grow straight out the side and I think back into the soil.
One tip if you do go with the 1 gallon. You can always "Wedding Cake" style it, which is where you cut about 1/3rd of the bottom off the smaller pot and put it into a larger 7 gallon pot and burry it about a 3 inches so it looks like a wedding cake. This way it allows the roots to grow into new soil. The drawbacks are you lost your
Smart pot.
But yes they are worth the money spent. You can re wash them. I take them to the Dry Cleaners after use. It is kinda funny looking at the people when you tell them you want them cleaned.