First you need an IDE (P-ATA) Blu Ray drive, second you need one with a height of 9.5mm, but as of now, it seems Blu Ray drives are at least 12.7mm high. You can get external Blu Ray drives though.
Theres some 9.5mm blu-ray drives floating around out there.
The real problem is that you need a GPU that can do bitstream decoding of video. Basically, the GPU needs to do all of the work. Thats something the Intel GPU in your Mac can't do and something OS X doesn't support. You need Windows and an nvidia or ATI GPU from the last few generations to be able to play blu-ray discs.