We decided to go to Hořovice on a fluke. The original map we were using, which we got from the AAA marks Hořovice way off the beaten path southwest of Prague (near the far lower right corner of this image). This map does indicate Terezin. Terezin was on our initial itinerary (with a link to the Wikipedia article even), but that was all. It does not list Lidice at all.
When in Berlin, we stopped off at the ADAC office (the German version of the AAA) and collected a number of maps. Among these were two that showed the area around Prague (Praha, Prag).
We used one of these (Deutschland Mitte #D 102) to mark our route from Berlin through Dresden to Prague. On our way into Prague we saw signs to Terezin. However, this map does not mention the town, nor does it mention Lidice (which the proprietor of the Anagram bookstore told us to see), nor Hořovice! Nonetheless, while studying the map Mark noticed a town called Horovicky (Horschowitz) which lays along the main road from Prague to Karlovy Vary (Karlsbad):
This renewed Mark's interest in visiting the site of the origin of the Hurvitz name. However, it was somewhat confusing. Nobody to whom we showed this map knew of any Jewish community that had ever existed in Horovicky. Though, one must admit, that the name does sound quite a lot like a possible variant reading of Hořovice (especially if you do not know Czech).
Clarifying, yet confusing as well, we had one other map from ADAC that covered essentially the same area (Polen Süd Tschechische Republik Slowakishe Republik #RR 24). This map showed all the towns we were interested in but did not indicate that odd little town of Horovicky (Horschowitz) which would have been a bit to the west of the town of Krupá. This does not seem to be the town from which the famous drummer's name originates.
The yellow highlight indicates the roads on which we drove.