There are several versions to choose from. They all work the same. Just pick whichever you like based on size, cost of parts, ease of soldering, ease of installing, etc.
Surface-Mount single-bank 96K easy to solder, polarity keyed, more expensive
Through-Hole single-bank 96K same as above, plus socketable/removable chips
Tiny single-bank 96K more difficult to solder, miniaturized mostly just as a stunt
Tiny dual-bank 192K most practical way to get all 192K if you can manage the soldering
PCB for STANDARD version from PCBWAY
BOM for STANDARD version from DigiKey
Same schematic as the standard version, just with all through-hole components.
The ICs may be socketed or not as you wish. When installed in the 600 there is room for both IC's on both boards to be socketed, and the BOM includes sockets.
PCB for THROUGH-HOLE version from PCBWAY
BOM for THROUGH-HOLE version from DigiKey
PCB for TINY version from PCBWAY
BOM for TINY version from DigiKey
Single board that plugs into both CN1 and CN2 and supplies all 192K at once.
PCB for DUAL version from PCBWAY
BOM for DUAL version from DigiKey
In 2017 I asked on the Tandy Color Computer Facebook group if anyone could clone a 96K ram board for Model 600, and Jayeson Lee-Steere produced Model600Sram_v1.1 and placed it in the public domain.
This version is different now but started from that.