Ibanez won't sell this part but as a replacement for their basses so you won't be able to get it unless you have an insider accomplice.
I have a Steinberger bridge that does the same thing.
Here again you won't be able to get it but as a replacement part from Hohner.
Your best bet is to buy a Hohner B-Bass (quite common second hand), vandalize it for its bridge, install a basic bridge and resell it.
Atlansia sells individual bridges with a D-Tuner. You can buy them from
their site.
They way they flip may be a limit to the kind of body shape you can use.
As far as I know, these 3 are the only detuner equiped bass bridges.
