Looking for a 4K switcher for video and Audio

[Barry]

I am looking for a 4K switcher with both a video and audio output. I am embarrassed to admit that I am totally ignorant in this area and I am asking for help, after reading about Lumagen Radiance Pro. 

I have a Krell 707 #D processor which is only 2K. I also have a JVC 3000 4K projector and a Panasonic 9000 4K disc player.

The JVC has two inputs. The Krell 707 is directly attached to in put one.  Going into the Krell are my 2K signals, Verizon Fios Cable box, My Amazon Fire Stick (which is 4k actually) and just the sound to my Panasonic 9000.

In the JVC’s second input I have a direct 4K cable connecting it directly to the Panasonic 4K disc player. The Panasonic has a second cable, just for sound, going into the Krell.

Is there a really good switcher that I can use to:
1. Switch my 4K video inputs.  This would be then be the Panasonic, The 4K fire stick and I would upgrade my cable box to a 4K which is w available.  (Only a few programs are native 4k, but maybe in time…)
2. I would need a second audio output going into the Krell for sound. (Krell has promised a 4k switcher specifically for the 707 but gosh knows when (and if) it will come out)

[TRainH2O]

I know that Krell would rather you move into a new Foundation 4K, but is there any word on the timeline on an upgrade for your 707?