Migs made a good point about the reason for the different size pistons and why flipping the caliper is necessary.

I noticed something confusing in regards to the Legend Calipers I would like to clear up for everyone.

If you want the Legend Dual Piston Caliper They are found on :

1993-1995 Coupes both L and LS trim. *THERE IS NO GS COUPE!*
1994-1995 GS Sedans.

The above where the "Type II" equiped Legends with the 230hp engine and optional 6-Speed Manual Transmission.

Finding the Coupes will be much easier since all 1993-1995 Coupes are Type II's where as only the very rare GS Sedan was the only Type II Sedan.

1991-1995 NSX Calipers will also work and are preferred but are more expensive.

PSPEC,
If you want to use the NSX caliper and Legend rotor go with the Legend's caliper braket. I personally think that would be your best bet.

When I had my Legend a few friends from a forum on Legend.Org did an NSX caliper swap on there Legend's. They only swapped calipers which leaves me to assume that if you are using the Legend rotor and braket the NSX caliper will work fine in your configuration.

And I don't think the ITR's rotors are 23mm thick either they should be thicker new at least 25 or 26mm's.