Spoke to an Allo tech person to ask some basic queries and understand their ecosystem.Recent purchase of Allo Digione player by one of the FM from fabtolab, confirmed it's RPi4 1GB model. If more RAM is needed, can go for buying separate parts and assemble. Otherwise no need to worry, can go ahead and order from fabtolab.
Waretohouse which is another Allo reseller was kind enough to connect me to them.
They have both RPI 3B+ and RPI 4B/1GB versions.
The Allo tech guy said for audio both RPI versions are fine.
RPI 4B runs a wee bit hotter (due to slightly faster clock)