DBT - Funny that I'd run across your post, just yesterday I was trying to decide how I might build a box to hold our hose.

I was leaning more toward a planter box I once had that was square. Do you remember the look of the redwood benches that sit atop the edges of two square planter boxes? They would work perfectly. About six inches from the bottom they had a removable shelf that would keep the plant (or in our case, the hose) up off the ground. This would be great for keeping the hose off the soil and you could easily build a wooden top with a hold drilled in it for sticking your finger in to lift off and sit aside. That way you could sit on it, without having to watch out of a dangerous knob! :)

The boards on the box I used to have ran vertical and it had a wider "frame" at the bottom and the top. Very similar to those in the link I've included.

I know I was a bit late in responding to your post... but maybe you're still seeking an answer.

Here is a link that might be useful: Redwood Box Visual Example