Right, to clear it all up:"
1080 (A1000 style)
1081 (brick model, nice dark tube!)
1084 (most common model, brick model like the 1081, powerbutton on the front)
1084s (same as above but with two speakers)
1084s-D1 (newer model, power button on the back)
1084s-D2 (newer model, white casing to match A600/A1200)
Considering the time line, the only "original" model monitor to go with the A500+ would be the 1084s-D1.
If you want to go MultiSync the model you'd be looking for is the 1950.
The 1960 is a newer model; also in the A600/A1200/A4000 colour. The 1438/1538/1764 are all later models from the Amiga Technologies era. (rebranded Microvitek monitors)
