Blu-ray recorders with internal hard drives do not allow you to load files up onto the drive. The internal hard drives are there to facilitate the recording of content in real time prior to burning that content to a DVD or Blu-ray disc. You can play content stored on the internal hard drive, but Blu-ray recorders do not have any network server capabilities.
You basically need both a DLNA uPnP certified NAS and some form of DLNA certified media player. Media player capabilities are included with some BD players. The NAS would act as a server from which a media player accessed stored media. Unlike the hard drive on a Blu-ray recorder you can load whatever you want onto the NAS drive. A Blu-ray player with media player capabilities and uPnP network access would be able to access the files you keep on the NAS via a LAN and the player's ethernet port.
Just about every modern Blu-ray player integrates a media player that can pull audio and video from a networked PC or storage device. The Dune B1 probably best meets your budget, but you'll still need to add an external NAS/HD.
Dune HD Smart B1 » Dune HD GmbH