Reddit mentions of IcyBox IB-3640SU3 External 4 Bay JBOD System for 3.5" SATA HDD USB 3.0

I did a bit of searching on your behalf and obviously I haven't tested it, (so please don't hold me responsible) but this looks like 99% the same thing as the Probox:

https://www.amazon.co.uk/RaidSonic-ICY-BOX-IB-3640SU3-drive/dp/B009DH5Q2S/ref=sr_1_35?ie=UTF8&qid=1504622540&sr=8-35&keywords=4+bay+esata

RaidSonic ICY BOX IB-3640SU3 - hard drive array
The Icybox External 4-bay JBOD enclosure for 4x 3.5” SATA l/ll/lll HDDs easy assembling by tray less design, HDD capacity unlimited, supports: Windows XP/Vista/Win7, MAC OS X. Plug & Play and Hot Swap. JBOD (Just a Bunch of Discs) JBOD, USB 3.0, eSATA

The reviews aren't too bad either from what I saw, so please let us know if you get one and it works well for you. :)

yes.

https://www.amazon.co.uk/IB-3640SU3-External-4-Bay-Enclosure-Silent/dp/B009DH5Q2S/ref=sr_1_2?ie=UTF8&qid=1486842257&sr=8-2&keywords=4+bay+esata

Dont think there's anything like that tbh.

Suggestions:
A standard TV hat case for the Pi4 with a USB3 JBOD enclosure.

For better cooling and performance but more expense consider fitting a Flirc case & ditching the TV hat for a USB tuner like the Happauge Dual-TV, allowing you to watch/record two channels simultaneously.