Hydraulic trailer surge brakes means no parking brake?

Forced to replace my snapped Komet III trailer tongue, the American/
modern answer for surge brakes seems to be hydraulic (versus
mechanical), or maybe electric. But either seems to eliminate the
possibility of parking brakes.

Without parking brakes, I'd have to use chalks. This is certainly
less convenient and I find the parking brake at the tongue to be
useful for hillside manual maneuvering of my trailer...

Any suggestions?

Thanks,

Eric
ER