Scans have been released for all Commander products previously apart from the Oversized promos.
For your records:
Commander - 5 different packs each of which had a 100 card deck and 3 oversized commanders. Due to the fact that some cards appeared in more than one deck (and basic lands), only 318 unique cards (by collector number) were printed in this set AND a total of only 15 foil oversized legendary creatures (wedge coloured commanders).
Commander's Arsenal - 10 foil oversized legendary creatures and 18 foil regular cards
Commander Promos - 5 enemy coloured foil oversized legendary creatures were given out for the release parties of Commander along with the deck you bought and played. Each of the 5 cards appears in only one of the decks as a regular (non foil) card.
Avacyn Restored
Helvault Prerelease Promos - These are very limited in quantity and were only available in the
Helvault prerelease kit. Some very special stores (picked by Wizards) got foil versions of these kits and other extras inside. For your records, 5 oversized legendary creatures were available in this kit all from Avacyn Restored. These were available as non foil and foil depending on the
Helvault prerelease you attended.
So only, 30 unique oversized Commanders exist in this format.
No other oversized promos have been released that match this, now standard, oversized printing. Previous direct mailers during the Magic Player Rewards era have included oversized versions of cards but without Magic backs so these are not technically "cards". Some of these were legendary creatures and could also be useful for Commander.
Hope this helps.