We have a winner

Celestron NexStar 5 SE

In the end, after much deliberation, we chose the Celestron NexStar 5 SE: we decided that it was the most portable option we were considering, and that portability trumped other considerations at this time.

We picked it up this evening, after work, at Focus Scientific, the local telescope store.

Now all we need is some clear, dark skies.