ah, after I posted that huge description, I'm thinking that you are using this for an audio only HT processor and it will be hard for you to find a monitor with analog video inputs that you can use for configuration (as everything is pretty much HDMI only these days). There are only a couple of processors that I know of which use the front panel for configuration - Bryston and Theta Digital. Actually, both are designed to just "pass through" any video signal and there is no onscreen menu, so you MUST use the front panel for configuration.
You can look for an older Bryston SP1.7 or SP2 processor, but there are none up for sale right now.
TMR Audio has a couple of older Theta processors that you can look at:
Theta Casablanca (version I) for $647. This is a basic "Generation 1 Theta" and has 5.1 outputs that are RCA only.
Theta Casablance II for $959. This is the generation 2 model and has much better DACs and audio stages (uses Theta Superior DAC cards), which also have balanced XLR outputs. On a side note, this model has a very rare AC-3 RF digital coax input. These RF digital connections were commonly used by Laserdisc players in the old days - not that you would really need this. lol If you had a laserdisc, you needed a separate RF demodulator unit that converted the digital RF signal to a normal digital coax signal.
Keep in mind that both the Bryston SP1.7/2 and these two Thetas are in the 15-20 year old range, which is about the same as your current Krell Showcase processor.