With the gear that you have now, I would give strong consideration to either the Mark Levinson 380 or 380S, both have the home theater bypass... go with the "S" version if you can swing it.
Alternately the Krell KRC-3 also has an HT blow-through circuit.
My first choice would be for the 380S.
Alternately the Krell KRC-3 also has an HT blow-through circuit.
My first choice would be for the 380S.