These are numbers 5 and 6 in the series:
1. R2-D2 in orange packaging
2. R2-Q5 - black droid
3. R4-P17 - Obi's droid from the prequels I think.
4. R2-D2 - dirty or battle damaged, I'm not sure, but the difference from the first R2-D2 isn't particularly significant, just some grey paint and new packaging with the 30th anniversary logo (presuming you can read Japanese.
Now these guys.
I know the first three can all be run at the same time because the radio frequencies are different, but not sure about the last R2 as I haven't tested it beside the others yet. I usually order mine from Robby.jp