Integrated Amp with HT by-pass

If you want to go used, Some newer Accuphase integrated have Ext PRE-IN, there is a E-450 @ $7k for sale.

Kzhtoo,
You could also just get a new preamp with HT passthru. I think tubed preamps paired with ss amps offers better results than all ss. I use a VTL 2.5 tube preamp with HT passthru with a ss amp and it not only improved 2-channel performance dramatically, it subtley improved HT sonic performance, too.

A properly selected tubed preamp with HT pass could do the same for you, with the added benefit of better 2-channel performance. Sorry, I'm not knowledgable enough to offer a good tubed preamp match with your excellent Pass amp but I'm sure some other members are.
Just an alternative to consider. Good luck.

Plinius

Also consider the Marantz PM11S3.

I bought two integrated amps this summer, both with HT bypass. The first is the Harman Kardon HK990, and the second is the Marantz PM-11S3. The HK sounds so good...I literally haven't opened the box of my Marantz. I will likely sell it. The HK is that good. It's worth a look.

There is also a company on here that modifies them, and I'm going to have that done this spring as well. :-D
Mot