@Rockhead,
There are some tall clumping (versus running) bamboos -
this is my favorite bamboo supplier; the woman who runs it is funny and bamboo wise.
http://www.endangeredspecies.com/Plants/Bamboo/bamboo.htm
The clumping Bambusa multiple var. Alphonse Karr works, or did for a friend/landscape architect, planted at ground level. It has fabulous leaf coloring. Does it grow in your area? Sunset says it's hardy down to 15 F.
15-35 feet high, can be contolled at 8 - 10 ft.
Isn't there an arboretum or japanese garden near you? sometimes those folks can be helpful.
I'm ever fond of Cupressocyparis leylandii (leyland cypress) - gets to 70 feet if let go, and it's a fast grower, but can work as a 15 foot hedge. But then it can be maintenance chore, and gets a fungus in some warm summer areas.
- There are galvanized steel containers that might work given adequate drainage holes - I dunno, since I've not played with those myself. Also not sure how they work with your local climate re summer heat.
- Maybe a raised bed - very raised - of cedar/redwood - or bricks veneering well built concrete block, with weep holes. All $$$$.
- Which brings up recycling lumber places - there are sometimes good finds at those.
- on metal containers - when we did city dump landscape design, we had some of the medium sized trash bins painted up, put in drainage, and planted them up. At this point I don't remember the paint or the drainage we set up.