I just need to choose one that is better quality that won't impact the 4K signal and also passes all the digital audio formats to my surround preamp.
You’ll want an audio splitter/extractor with 4K support, thus HDMI 2.0 ports (18 Gbps) and HDCP 2.2 support. Do not get an HDMI 1.4 version, even if they claim 4K, because 4K without HDCP 2.2 support is useless.
For digital audio, you’ll want Toslink (optical) or RCA (coaxial copper, typically orange colored cables) to carry the S/PDIF protocol signal. Of course look to match the capabilities of your audio equipment (Toslink or RCA digital audio).
The common red/white RCA ports carry analog stereo audio, so that is not good enough for your use. More of a ‘last resort’.
The signal is digital, so it will go through 100%, or not at all. There should be no further processing.
Quality differences will be in the build, not the signal.