I decided to go for the XYC X30 from banggood. It was reasonably priced, is silent (fanless), and has low power consumption.
As it comes from Banggood, it is a bare bones system, so requires RAM, storage, and Wifi (if you want to add it)
Ram: There's a slight downside here as it will only support a maximum of 8Gb and only has one slot, so I inserted my 8Gb module and moved on!
Storage: There's one on board SSD slot, and one SATA port (with SATA cable included) I don't have a SSD spare, and wasn't bothered about the speed defecit of spinning media, so I installed a spare 360Gb 2.5" drive which has been lying around for a while waiting for something to do!