Hey Jack,
If I were to make a move it would be to replace both pre-amp and DAC. I believe the W4S DAC is an excellent DAC and I do not imagine getting an improvement there unless I were to go with something like a Lampi, etc.

.... The idea is to simplify being able to connect all sources to one unit and simply select the source I want to listen to. However the last thing I would want to do is sacrifice sound quality in any way. Therefore doing some basic initial investigations.
I have considered McIntosh C47 (growing up in Binghamton any consideration means that a Mc version is thrown in). I have also thought about the matching SST. Nice pre-amp which can have all of the options thrown in. I was reading about the Brooklyn in TAS that arrived over the weekend. It seems to have a lot built in for the price. Pre-amp, headphone amp, DAC up to DSD256, ESS9018, Femto clock, MQA (does not really matter to me), all inputs both digital and analog (with built in phone preamp, not that this is a big deal to me), both balance and unbalanced outputs, made in the USA, remote functions through a Windows application, etc.
Seems like an awful lot of functionality for the price. But, is it a compromise in SQ? So this was my reasoning for investigation.
It is not like I have any reason to want to get rid of my STP-SE and DAC-1 LE. Just having to set the proper combination on the pre-amp and DAC for the particular source is the only real inconvenience

.... (headphone amplifier would be nice, which Mc and SST both have also).