If you want to keep it really authentic, System 6 came out in 1988 and the last release was 1991. That put it past the Plus by a few years however puts it in the SE or SE/30 if you are into compacts and the II or IIx if you are into full NuBus. This also means that again you are in the SWDL realm so you're like me again when it comes to finding the components. Some things like the scanner and modem were excessively annoying to get hold of.