That should be good for the space. Just plan on building up layers of litter over time to keep the composting process going. If I slack on adding wood chips for too long and the layers get too compacted, that's really the only time I start noticing odor problems.
I would not recommend sand, you only get one season a year that it'll dry out, especially with an unroofed run. If you ever played in a freshly rained upon sandbox as a kid, remember how clumpy the sand could get? That's what 3/4ths of the year would look like for you.
So here's the scoop...