Most of the Wilwood calipers don't come with rubber boots but yes the dynapro calipers that I have are boosted. You can get them booted or unbooted with SS pistons, for more of a track setup.

With that said, I'm not sure the unbooted calipers are much of an issue. Out of all the unbooted kits that TCE has sold, they said they have only had about 2 that failed and this was after many years of use, in winter/salt conditions as well.