AFAIK you won't find any support from the blu ray player manufacturers for recognizing external disks/drives using a mac format. You will usually require FAT32 with a smidgen of support for NTFS.
If accessing that file system is a requirement, I'd agree with Bob who suggested a laptop with built in BD player. You also gain a lot more flexibility and horsepower with such a device.
See if you any of the big box stores offer a name brand lappy with an Intel i3-330m chipset, Blu Ray drive and HDMI out port. I'm guessing the lower end you will see (if any) would be around $700-800 for such a laptop. More will likely have i5 or i7 chipsets (=$$$). Core 2 Duo would be my second choice- perhaps a closeout model with a blu ray drive under the hood. YMMV- just poke around a little in the weekly flyers.