I am looking for a TV box for my caravan and really need two things 1) must run off either usb 5v or vehicle 12v and 2) supports up to 4tb external usb hdd.

I can find plenty that meet requirement 1) but can't find anything that works for 1 & 2...

I use (and love) nvidia shield in the house, but it does not meet my voltage criteria (without a dc2dc converter) and is also overpriced for my caravan needs.