I'm not certain the max bitrate the PS3 supports, but if you can't remux then I suggest using x264's constant quality mode. RF 16-18 (lower is higher quality) and tune "grain" to preserve the film grain.
Normally I'd suggest a higher RF number but typically more quality is needed when recompressing multiple times. x264 does a relatively good job in these cases but a slightly lower RF (more bits) makes the conversion more transparent.