The system is great, the Krell HT Standard lacks the HDMI connectivity and the latest codecs. The DAC’s are pretty dated, but might still sound nice.
I would keep everything else and contact a Krell dealer to see about exchanging it for something from the last 5 years that has a 4K capable HDMI connection and modern room correction software. The amps and speakers are very nice. If you want the cheapest solution possible you could get a Sony UBP 800 blueray player which has internal decoding and two hdmi outputs. Hook the HDMI or spdif for audio out to the Krell processor and the other one out to your video display: