You can always get the CB and convert it:
(From the TB website) With the CB mount, the suppressor mates to a conical shoulder on the brake and locks up rock solid and extremely tight. In direct thread configuration, the ULTRA suppressors use a heat-treated 17-4 thread insert and initial blast shield. The ULTRA series suppressors also have the flexibility to be changed from direct thread to CB mount and vice versa via a simple factory service operation, in case your needs change. This is accomplished by removing or replacing the default brake from the direct thread version.