Research Question - Traditional Sources

I have now blogged about the Horeb / Sinai issue from the DH perspective. I am now looking at traditional explanations for the use of these two names, and I have a general methodological question: how do I research this in particular, and similar issues in general?

I have a few approaches:

1. Look at a Torah with commentary. (Rashi, etc.) The problem here is that this requires looking at each of the 40 or so instances of Sinai and Horeb to see if there is comment.

2. Poke around the web. I've found some general sources that reference other things. Like a short Talmudic discussion in Shabbat 89a-89b.

3. Check sources that argue against the DH. I've found a brief passage discussing this issue in Eisenstein's Commentary on the Torah. Nothing in R. Etshalom's book or Cassuto's book.

But other than these three approaches (Torah w/ commentary, web, traditional sources on DH), can someone think of a good way of researching this textual issue in particular, and similar textual issues in general?