Data and Phone Patch Panels - more
While researching these alternatives, I found that punch-down "connection systems" are available (such as Siemon's S210) that are rated for up to CAT6 termination! This meant that I could use either flavor of patch panel for both data and phone drops.
In the end, however, I opted for using two 12-position CAT5e RJ45-style panels for both data and phone drops, with three things influencing my decision. The first was that I would have ended up having to make jumper cables to go from the punch-down block to RJ45 plugs for any of my data connections. (I could have purchased these cables, but the cost was prohibitive.)
The second reason was that punchdown blocks are more intended for terminating large multi-line trunk cables so that they can be cross-connected to individual phone jacks instead of connecting multiple phones to a single telco line. While techniques exist for connecting multiple drops to a single phone line, they're not really recommended.
In the end, the thing that tipped the scales toward using RJ45-style patch panels was my discovery of Leviton's 47609-EMP Telephone Patching Expansion Board (Figure 9). While it was a bit pricey at around $26 at SmartHomeUSA.com, it did the trick for me, with the ability to connect up to seven phone drops to up to four telco lines.
Figure 9: Leviton Telephone Patching Expansion Board
Although seven drops was not enough to support all of my planned phone jacks, it was fine to at least get me started. And I could always use just plain ol' phone jack-splitters in a pinch if I ran out of jacks on the board.