How to get the best quality blu ray for a film festival screening

Can a blu Ray play 5.1 sound? And if I'm burning a blu Ray myself thru FCP X will it be just as good as having it done at a post house? Do I lose any quality? I'm doing it thru FCP X NOT thru compressor. Would that make a difference/better quality? Basically how do I get the best quality Blu-ray? And how important is my Blu-ray burner?