I'm a big fan of self-watering containers, like the Earthbox, but I'm not a big fan of the Earthbox price at around $50 on Amazon and considerably more in local retail stores.
I blogged about a method of making cheap self-watering containers using buckets, but I've also found that I like the City Pickers self-watering garden kit that Home Depot sells for $30.
They show it being used for tomatoes, but I wouldn't recommend that. Even if you choose a smaller variety bush tomato, like a Patio Tomato, you'll find that tomatoes have vigorous root systems and you'll probably have nutrient problems. The "trellis" that comes with it isn't particulary suitable for much either.
This year, I'm going to try growing pickling cucumbers in this planter. and with that, I've found yet another use for an inexpensive product I found at The Home Depot called "mason ladder". Don't bother googling this term, it won't do you any good. Mason Ladder is a 10' section of heavy gauge galvanized wire, about 4" wide with cross connectors every 12".
Anyway, I stuck a couple of these mason ladder pieces in my City Pickers planter, and I think it will make an excellent cucumber trellis. Here's a pic!