If you don't already have the 4k monitors, just get one with a thunderbolt input/output. A slightly more expensive dell monitor with good thunderbolt/usb-c support basically replaced my $300 dock, and it only cost about $100 more than the cheaper 4K monitors. Mine takes thunderbolt input, provides one usb-c port, and 4 usb-3 ports. Daisy chaining is supported, but note that you can't run 2 4k@60hz monitors with peripherals on a single cable - see details below.
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Your setup needs will also depend on whether you plan to run two monitors with 4k@60hz.
I was trying to run a setup that would give me two secondary displays plus peripherals on a single thunderbolt cable, but the unfortunate reality is that it's just not fast enough.
Thunderbolt gets you ~40gb/s. A 4k@60hz monitor needs ~19gb/s, and a usb-3 hub will need another 10gb/s.
Two monitors + a hub means you need ~50gb/s and the connection just doesn't support that.
In windows things will almost always gracefully degrade (one monitor will drop to 4k@30hz). In linux... it's a bit of a grab bag depending on the order the devices are detected - Sometimes one monitor will fail to be discovered at all, sometimes usb devices will never be powered up, in some cases you'll see one (or sometimes both) monitors come up but no longer offer the correct resolutions.
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Once I realized I was hitting the throughput limits on the cable, I caved and moved to a setup that used two thunderbolt cables plugged into the laptop.
I'm fortunate that my work and personal machines both have two thunderbolt ports (mac work work, xps 13 for personal) and they can both be charged from the same cable.