Jeff Rowland Concerto Integrated has two sets of XLR preamp outputs and two sets of XLR inputs but it is more expensive than the Concentra.
In response to the post above, the McIntosh MA2275 integrated does not have balanced outputs. Only one balanced input and RCA outputs. Same with the with McIntosh 6900. I'm pretty sure that neither the Mac 6500 or the 6300 have balanced outputs. Mark Levinson 383 offers two balanced inputs but not a balanced output. In fact, I don't think the 383 has any preamp outputs. It does have an RCA output for the tape monitor though.
I think the Concerto is a fantastic product provided the rest of your system does not lean to the bright side. Good luck.