depends on which one you have.
many replace the Concertone Chassis Group "B" units, with the Jensen AWM 965 or 975 model.
if your Concertone is a Chassis Group "A" unit, there's not much out there other than Concertone, to replace it.
unless you mod the opening to fit the "B" sized ones.
here's Concertone's product gallery to find which one yours is:
Concertone® Product Gallery
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC