That earth box idea is interesting Kisal. I have heard not-so-good things about planting edible fruit in plastic, though. I'm concerned about that. But the concept seems wonderful.
Blunt - I have never grown tomatoes before, and don't have any experience with 5 gallon buckets or self-watering containers, but I can comment to your idea of punching the holes up closer to the roots. This will not accomplish what you're thinking it will. I believe you are thinking that extra water will collect in the bottom, thus forming a 'reservoir' in the bottom of the bucket. However, this is not how the plant will see it. The plant will see it as the ground being flooded, and it will have it's roots in standing water, which in fact sort of 'drowns' the plant from the roots up. The idea that the holes could be 'below the roots' is somewhat deceiving. The holes could be 'below the roots' if the plant is still very young. By the end of the growing season, though, those roots will completely fill up the bucket. There will not be any 'below the roots' space.
I hope that answered at least one question for you! Good luck on the rest of it!