  The MeerKAT telescope will be one of the most sensitive radio arrays in the
pre-SKA era. Here we discuss a low-frequency SZ-selected cluster survey with
MeerKAT, the MeerKAT Extended Relics, Giant Halos, and Extragalactic Radio
Sources (MERGHERS) survey. The primary goal of this survey is to detect faint
signatures of diffuse cluster emission, specifically radio halos and relics.
SZ-selected cluster samples offer a homogeneous, mass-limited set of targets
out to higher redshift than X-ray samples. MeerKAT is sensitive enough to
detect diffuse radio emission at the faint levels expected in low-mass and
high-redshift clusters, thereby enabling radio halo and relic formation
theories to be tested with a larger statistical sample over a significantly
expanded phase space. Complementary multiwavelength follow-up observations will
provide a more complete picture of any clusters found to host diffuse emission,
thereby enhancing the scientific return of the MERGHERS survey.
