@mightyhatter 

Hey

There really isnt much choice in POE passive switches, but the ubiquiti you mentioned I have come accross before and it generally seems to work well! 

The other option, should you want to keep the switch managed would be to use a POE injector / Seperator to power any switch you want at the far side.    Incase you havent come accross these before, they inject POE over a cable, then at the other side remove it and allow you to plug your device into it.   Fundamentally you can power anything that is low enough wattage.

https://www.amazon.co.uk/TP-LINK-TL-PoE10R-TL-POE10R-PoE-Splitter/dp/B001PS4NWW

  @mightyhatter 

The TL-SG2008 v3 can be powered by PoE on port 8. I've been using it that way for a few months because I had limited power outlets.

  @Insomnic 

I wasnt actually aware of that, nice one!    Looking at the site the V4 is also POE powered

Every days a school day!  :)

Thanks all for the suggestions. I had a slight rethink and I think I'm going to run a Deco X50-POE from the TL-SG108PE switch and connect the second ethernet port from there to a switch with a power supply.